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I started my talk by playing a short extract from the beginning of Music For 18 Musicians by Steve Reich:

David Saunders played the CD from Reich's Collected Works, but here it is on Spotify.

I first heard Music for 18 Musicians on the radio lying in bed ill when a graduate student in Leeds in the late 1970s. I thought it was wonderful at the time, and I still do.

Rob Cowan, writing in a review of the recent box set of Steve Reich's Collected Works, had a similar experience:

My first encounter with Steve Reich’s music was over fifty years ago as a skint newlywed in a small attic bedsit. With no funds to buy – or even rent – a TV, we had two sets placed next to each other on the windowsill, one with vision and no sound, the other with sound and no vision. One night lolloping on the bed goggle-eyed, I tuned in to a bunch of musicians playing what seemed like an endless sequence of repetitions. Then, unbelieving that anyone could fashion music out of such a deceptively simple process, I began to really listen.

The work in question was Reich’s Music for Eighteen Musicians, represented on this new Collected Works set by two recordings (discs 5 and 27), the first mixed between 1996 and 1997, the second, a 2011 PIAS/Harmonia Mundi recording issued under license to Nonesuch - though the differences between the two versions, each with hypnotic pulse patterns that harmonically change at the prompt of a vibraphone, are minimal. You submit to ‘MEM’ and are hooked for the duration: here is a man who melds the intellect with the senses. Not for Reich hardcore discordance locked in a padded cell, but endless journeys where you soak up the passing scenery, stimulated further by the rhythmic pounding of wheels on tracks though never with a hint of aggression.

What is Minimalism?

It's a blanket term that was applied to a body of music that emerged during a period of roughly 20 years between the late 1950s and the mid 1970s.

I'll be concentrating on the 'Big Four' minimalist composers: La Monte Young, Terry Riley, Steve Reich and Philip Glass.

• It was American. It took place mostly in the cities of the West Coast and East Coast, principally San Francisco, Los Angeles and New York
• It was a reaction against the reign of the serial, atonal and 12-tone music that dominated the musical establishment in the mid 20th century
• It was heavily influenced by modern jazz, the be-bop of musicians like John Coltrane, Miles Davis, Charlie Parker. Composers envied their freedom of expression.
• Influenced by the ideas of John Cage. He staged a performance of Satie's Vexations in 1963. But the Minimalists went their own way.
• Influenced also by non-Western musics, especially African and Indian. Recordings of these were just becoming readily available
• It took ideas from Art - painting and sculpture - which had its own Minimalist movement before the term was applied to music. Also the anti-art Fluxus movement. Canvases that might be all one colour, or no colours, or no canvas.
• It has to be said that the hippy and drug culture of the 1960s played a part and the downtown scene of New York's Greenwich Village and SoHo areas in the 60s and 70s. In practical terms the low rents for large loft spaces meant musicians had access to spaces where concerts and 'happenings' could be staged .
• There was also a part played by newly available, and increasingly affordable, technology, particularly tape recording, electronic organs, mixing desk equipment and so on.

Vexations

Vexations is a piece by Eric Satie. It's not very long; but the instructions say that it has to be played 840 times.

John Cage promoted a full performance of Vexations on September 9th and 10th 1963. Ten pianists played in relays. Admission was $5, refunded 20¢ for each 20 minutes you stayed and 20¢ bonus if you stayed the entire programme. The New York Times wrote that after 18 hours and 40 minutes it ended with 'a spattering of applause, then great applause…cries of bravo, and one yell of encore. One person collected the full refund of $3 and said it was 'a great experience'. You can read the full report in the New York Times of September 11th 1963.

Atonal Music

All the major figures who created Minimalism were highly trained musicians, and for the most part had studied in the 12-tone school with eminent teachers such as Luciano Berio. Steve Reich studied with Nadia Boulanger. So did Terry Riley (but only briefly).

Steve Reich said 'Don't get me wrong. Berg, Schoenberg and Webern were very great composers. But to create Pierrot Lunaire in Ohio, or in the back of a Burger King is simply a joke.

Philip Glass was critical of Boulez and the European serialists in the 1960s, and spoke of 'a wasteland, dominated by these maniacs, these creeps, who were trying to make everyone write this crazy creepy music'.

A professional musician I spoke to last year said that he and his colleagues sometimes refer to the more outlandish atonal music they are asked to play as 'squeaky gate music'. Personally, listening to it always reminds me of the game we used to play as children, where you try not to step on the cracks between paving stones. To me, such music always seems as if it is deliberately avoiding the right notes.

At this point I (rather unfairly) played part of Le marteau sans maître by Pierre Boulez as an illustration of 'squeaky gate music':

Jazz

La Monte Young was a very fine jazz saxophonist and could have had a jazz career: he once beat out Eric Dolphy in an audition for a jazz band. Terry Riley mastered ragtime piano and saxophone. Reich and Glass were big jazz fans.

Summary

Composer David Lang summed it up thus:

Minimalism was a historic reaction to a sort of music which had a stranglehold on American institutions, and which none of us really liked…I look at Minimalism as being just the battleground that was necessary to remove these forces from power…one reason why Glass's music and Reich's music came out so severe and so pared down, was that…it was a polemical slap in the face…That battle's been fought…My job is to sift among the ashes and rebuild something.

The term 'Minimalism'

It wasn't the composers who invented the term 'Minimalism'. It was bestowed on them by writers and critics. When they wrote about the uncanny, slowed-down music they were hearing in San Francisco and downtown New York, they used terms like 'drone-based', 'repetitive' or 'modal'. The term 'minimalist' first cropped up when British critic Jill Philips described a 1968 performance of La Monte Young's Death Chant as a 'minimalist piece'.

The composers themselves were often uncomfortable with the term. Record company executive Robert Hurwitz tells the story that back in 1975 he had remarked to a young composer that he had no interest in Minimalism. When Steve Reich came to his office a year later, the first words out of Reich's mouth were 'I hear you hate Minimalism—and so do I.'

(Robert Hurwitz ran the American operation of European label ECM records and went on to be the president of Nonesuch records from 1984–2017.)

In 1972 composer and journalist Tom Johnson declared the existence of what he called a 'New York Hypnotic School': 'Some of their pieces employ traditional scales and some do not. Some of them chug along with a persistent beat and some float by without any rhythmic articulation. Most of them are loud and employ electronic resources. And some employ standard instruments without amplification or electronic manipulation of any kind. Yet they all have the same basic concern, which can be described as flat, static, minimal, and hypnotic.'

In 1977 Johnson wrote an amusing piece for the Village Voice in which he attempted to show what minimalism was by writing the article in a 'minimalist' style. You can read it here.

There are some pieces of classical music that might be seen as minimalism before Minimalism:

• Ravel: Boléro
• Wagner: Prelude to Rheingold (begins with 156 bars of the same E♭ major triad)
• Satie: Vexations
• Sibelius: The Wood Nymph, middle section

Four men are very often regarded as the founders of Minimalism, all born within the same two years:

• La Monte Young, born Oct 1935
• Terry Riley, born June 1935
• Steve Reich, born Oct 1936
• Philip Glass, born June 1937

As of February 2026, these gentlemen are all still alive at or approaching ninety years of age.

The book On Minimalism by Kerry O'Brien and William Robin, sets out to tell an alternative story about the many other figures who contributed to the movement, but confesses in its introduction that the canonical tale is usually told about those four:

There's a story you may have heard; it gets repeated a lot. It's one story, but it's about four people. In 1958 in Los Angeles, a twenty-two-year-old composer named La Monte Young wrote a piece in which, over the course of nearly an hour, hardly anything happens: three string instruments play extraordinarily lengthy, still tones interspersed with silence. A short while later, in grad school in Berkeley, Young met Terry Riley, who became similarly preoccupied with music that moved at a glacial pace. After a stint in Paris, Riley wrote In C, a score that instructs a group of instrumentalists to repeat a series of short riffs that accrue into a wash of sound. At a rehearsal for In C before its premiere in 1964, Riley's San Francisco neighbour, Steve Reich—a percussionist and budding composer—suggested that the musicians might be able to stay together more easily if someone constantly struck two C keys on the piano, to provide a steady pulse. Not long afterward, Reich spliced recordings of a street preacher's voice to create a soundscape of eerie and unexpected acoustic effects. After moving back to New York, Reich held a retrospective of his music, where he re-encountered an old Julliard classmate, Philip Glass. Glass joined Reich's ensemble of musicians, whom he recruited to play new scores based on his tape experiments with close musical canons. And Reich joined a similar group created by his friend, with which Glass was developing an idiosyncratic style, influenced by Indian ragas, in which repetitive musical phrases hypnotically expanded and contracted. Young's drones, Riley's loops, Reich's pulses and phasing, Glass's additive processes. Each composer pioneered a set of techniques that built the most important and influential movement in avant-garde music of the late twentieth century: minimalism. Over the span of a little more than a decade, minimalist music went from austere long tones and grating harmonies to toe-tapping, accessible tonality. Glass and Reich have since become household names, selling millions of records and influencing pop culture from movie soundtracks to David Bowie songs; Young and Riley remain cult figures, but essential protagonists in minimalism's origins. They weren't the Beatles, but sometimes the quartet is called the 'Fab Four'.

Bearing in mind that it is not the whole story, I am going to have to limit myself to the 'Big Four' (on the night I didn't even get to Philip Glass!)

La Monte Young was born in Bern, Idaho on October 14th 1935, in an actual log cabin. At an early age he learned guitar, saxophone and tap-dancing. Later he became fascinated by jazz musicians such as John Coltrane, Lee Konitz and Eric Dolphy (saxophonists, composers and band leaders). From 1955–1956 he studied composition with Leonard Stein, a colleague of Schoenberg. At UCLA he studied music theory, composition and ethno-musicology. In summer 1959 he attended Stockhausen's seminars in Darmstadt and made an intensive study of John Cage's works. In 1960 he went to New York to study electronic music with Richard Maxfield in the 'New School For Social Research' where he also met George Macuinas (of the Fluxus art movement). Then he began to write music. With Macuinas and Jackson MacLow he set up 'performances' involving Joseph Byrd, Henry Flynt, Richard Maxfield and Toshi Ichyangi. Worked with choreographer Ann Halprin. In 1963 Young married the painter and light artist Marian Zazeela and formed with her 'The Theatre of Eternal Music' which also included Tony Conrad and John Cale (a Welshman, who later was a founding member of Velvet Underground).

Note that, like the others, he starts off on the West Coast, and migrates to the East Coast and New York.

His music can be divided into three periods

1. 1956–1958 he wrote serial music
2. 1959–1961 he was part of Fluxus
3. 1962– his repetitive period begins

Young was fascinated by something he heard in the music of Webern: his tendency to repeat pitches at the same octave position. Young heard this as the constant repetition of material—to him, twelve-tone music became understood as 'the same material repeated over and over again, in strictly permuted transpositions and forms, which recalls the 13th century use of cantus firmus'.

This developed into one of Young's techniques: very long held notes.

The String Trio of 1958

For violin, viola and cello, or string orchestra. Long, lo-o-o-ng notes, and somewhat less long periods of silence. Use of long notes was not novel, but hitherto were only a drone over which a melody was heard. For Young the long notes are the one and only subject of the music. Young coins the term 'sustenance' for this.

The string trio shows Young feeling his way towards a combination of tones which he called 'The Dream Chord', inspired by his childhood experience of listening to the hum of telephone wires in rural Ohio. The Dream Chords (there were eventually four or more of them) consist of perfectly tuned intervals based on fifths, sevenths and seconds. He avoids intervals of a third: 'I began to realize, he said, 'that this interval of a major third did not convey any of the feelings I was interested in'.

Fluxus

Around 1959–1960 Young is influenced by the 'anti-art' Fluxus movement.

Fluxus Manifesto (1963)
by George Maciunas

Fluxus intends to purge the world of bourgeois sickness,
“intellectual”, professional and commercialized culture.

Fluxus will promote a revolutionary flood and tide in art,
promoting non-art reality to be grasped by all peoples, not only critics, dilettantes and professionals.

Fluxus will fuse the cadres of cultural, social and political revolutionaries
into united front and action.

If man could experience the world — the concrete world
surrounding him (from mathematical ideas to physical matter) —
in the same way he experiences art, there would be no need for art,
artists and similar “non-productive” elements.

Thus inspired, Young produces a set of 'Compositions 1960':

    Piano Piece for David Tudor #1

    Bring a bale of hay and a bucket
    of water onto the stage for the
    piano to eat and drink. The
    performer may then feed the piano
    or leave it to eat by itself. If the
    former, the piece is over after
    the piano has been fed. If the
    latter, it is over after the piano
    eats, or decides not to.

    Composition 1960 #2

    Build a fire in front of the audience. Preferably, use wood al-
    though other combustibles may be used as necessary for starting
    the fire, or controlling the kind of smoke. The fire may be of
    any size, but it should not be the kind which is associated
    with another object, such as a candle or a cigarette lighter.
    The lights may be turned out.

    After the fire is burning, the builder(s) may sit by and watch
    it for the duration of the composition; however, he(they) should
    not sit between the fire and the audience in order that its mem-
    bers will be able to see and enjoy the fire.

    The composition may be of any duration.

    In the event that the performance is broadcast, the microphone
    may be brought up close to the fire.

    Composition 1960 #3

    Announce to the audience when the piece will begin and end
    if there is a limit on duration. It may be of any duration.
    Then announce that everyone may do whatever he wishes for
    the duration of the composition.

    Composition 1960 #4

    Announce to the audience that the lights will be turned off for
    the duration of the composition (it may be of any length) and tell
    them when the composition will begin and end.

    Turn off all the lights for the duration of the composition.

    When the lights are turned back on again, the announcer may tell the
    audience that their activities have been the composition, al-
    though this is not at all necessary.

At this point I announced that I would perform Composition 1960 #7 in its entirety. I went to the Keene Room piano and struck the notes B below middle C and F♯ above it together, and held them until the sound died away. That was it!

Another important element in Young's mature style was the interest in what he called 'just intonation'. That is, tuning the intervals between pitches to the exact mathematical ratios of their frequencies instead of traditional 'equal temperament', the slightly off tuning which enables music to be played using all twelve tones of the chromatic scale.

In order to fully appreciate the harmonics that appear in this music it was sometimes necessary to use very high levels of amplification. Young suffered from hearing loss in later life.

Some of his other compositions, performances or events (it's difficult to know what to call them) were

• The Second Dream of the High-Tension Line Step-Down Transformer
• The Tortoise, His Dreams and Journeys

Another idea is that a piece could start and run forever. The first of these was established in Young's own New York loft home. It ran from September 1966 and continued almost without interruption until January 1970.

To get a flavour of what it was like to be at some of these performances, read Tom Johnson: La Monte Young Diary 1968–1973.

The Well-Tuned Piano

Young acquired a piano from his wife's parents in 1964. Nearly 30 years old, he'd never had access to a piano of his own before. He set about re-tuning it in just intonation.

There is a YouTube video of La Monte Young performing The Well-Tuned Piano in New York in 1987. The recording is six and a half hours long!

It's been performed in public at least 60 times, but not since 1987. It takes a couple of weeks to tune the piano. In fact Young asks for three months to arrange a performance.

Born in Colfax California on 24th June 1935 (so he's the oldest of the Big Four). From 1955–1957 he studied composition with Seymour Shifrin at the San Francisco State College. Later worked under Robert Erickson, studied piano with Duane Hampton at the San Francisco Conservatoire of Music with Adolf Baller. Worked as a ragtime pianist at the Gold Street Saloon in SF. He met La Monte Young in Shifrin's class and they became friends.

Riley is the archetypal hippy, the sunniest and most laid-back of the Big Four. He is the only one of them who is smiling in nearly all his pictures.

Career in three broad parts: childhood and student years in Northern California; away from the West Coast largely in France and New York, but also in Scandinavia, Morocco and Mexico; then return to rural California where he has lived ever since.

Started experimenting with tape assisted by Richard Maxfield. Using cheap mono reel-to-reel recorders he made his first tape loops recording piano, speech, laughter and other found sounds. Used them in dance pieces for Ann Halprin, variously called The Three Legged Stool, The Four-Legged Stool, and The Five-Legged Stool. Later he used these tapes as a basis of a composition called Mescalin Mix. He made use of an Echoplex, a primitive electronic contraption allowing a sound to be repeated in ever-accumulating counterpoint against itself.

Richard Maxfield 1927–1969 pioneer in using tape: 'the simultaneous performance of improvised instrumental solos with tapes based upon samples of the same soloist'. Maxfield killed himself aged 42 by jumping out of a window in Los Angeles.

Then Riley found a way to do without the Echoplex and get even better effects. The link below takes you to the point in an interview where Riley explains this; but the entire interview is well worth viewing.
Terry Riley talks about how he came upon the dual tape recorder technique in Paris in 1963

In C

Riley wrote In C in San Francisco in 1964, 'using the techniques I'd developed in Paris'. Premiered at the San Francisco Tape Center in November. Between composition and premiere, Riley had met Steve Reich. Despite their 'considerable differences of temperament' they became, for a while, close friends. Reich offered to get an ensemble together to play Riley's new piece. Composition of the group varied from rehearsal to rehearsal, it was 'whoever I could get to play for nothing - some of those who played at the premiere had never played the piece before'. There was a high degree of collective input: 'the room was always full of composers and people were always making suggestions'. Riley thinks Reich is correct in saying that adding the pulse was Reich's idea (it proved impossible to play the piece without some form of time-keeper).

The piece consists of 53 separate modules of roughly one bar apiece, each containing a different musical pattern, but each, as the title implies, in the key of C. One performer beats a steady pulse of Cs on the piano to keep tempo. The others, in any number and on any instrument, perform these musical modules following a few loose guidelines, with the different musical modules interlocking in various ways as time goes on.

The original performance evolved by consensus without any written instructions. The composer has encouraged subsequent performances over the years to be an exploration of its potential rather than a faithful reproduction of the score. In C, says one critic, resembles more a kind of urban folk music than a conventional composition.

It's scored for 'any number of any kind of instrument'. Not all performers need to play all the modules—some suit piano or percussive instruments; some are more suited to wind instruments.

After the pulse has started, each performer can enter with module 1 in his or her own time, then repeat as often as they wish before moving on to the next one. While performers are free to move from module to module, and may omit some, they should not leap ahead of the majority. There should be no more than three or four modules in play at any time; the group should try to merge into unison at least once or twice; once a performer reaches the last module he should repeat it until the others catch up; then crescendos and diminuendos, and finally the musicians drop out one by one to end the piece.

Here is In C on Spotify:

I've seen an analysis of the piece which suggests that 'In C' is not really 'in C' at all, suggesting that the tonality moves at times to G, E minor and various 'modes' with names like Lydian and Mixolydian.

Alfred Frankenstein's review in the San Francisco Chronicle 1964:

This primitivistic music goes on and on. It is formidably repetitious, but harmonic changes are slowly introduced into it; there are melodic variations and contrasts of rhythm within a framework of relentless continuity, and climaxes of great sonority and high complexity appear and are dissolved in the endlessness. At times you feel as if you have never done anything all your life long but listen to this music and as if that is all there is or ever will be, but it is altogether absorbing, exciting and moving too.

Poppy Nogood and the Phantom Band

This is Riley improvising on electric organ and soprano saxophone, subjecting both to delays using the time-lag accumulator.

The title is often said to be an allusion to drugs, but it actually arose from the fact that Riley was calling himself 'Poppy Nogood' at this time. His small daughter used to call him 'Poppy', and 'Poppy Nogood' when she was angry with him.

Rainbow in Curved Air

After that, Riley focused more on keyboards. More sophisticated types of instruments were becoming available to him. The influence of Indian classical music is more apparent, from the tapes of Pandit Pran Nath which Young has played to him.

Rainbow in Curved Air is available on CD. The CD insert contains a poem, typical of the love and peace hopes of the hippy 1960s:

  And then all wars ended
  Arms of every kind were outlawed and the masses gladly contributed them to
    giant foundries in which they were melted down and the metal poured back into
    the earth.
  The Pentagon was turned on its side and painted purple, yellow and green
  All boundaries were dissolved
  The slaughter of animals was forbidden
  The whole of lower Manhattan became a meadow in which unfortunates from the
    Bowery were allowed to live out their fantasies in the sunshine and were cured
  People swam in the sparkling rivers under blue skies streaked only with
    incense pouring from the new factories
  The energy from dismantled nuclear weapons provided free heat and light
  World health was restored
  An abundance of organic vegetables, fruits and grains was growing wild along
    the discarded highways
  National flags were sown together into brightly colored circus tents under
    which politicians were allowed to perform harmless theatrical games
  The concept of work was forgotten

All that apart, I really enjoy Rainbow in Curved Air. It's warm and sunny music. Riley embraced the interval of a major third, which La Monte Young had cast aside. (Though on a bad day it can sound like a lot of ring tones run together!)

Born in New York on 3rd October 1936. Studied philosophy at Cornell University and composition at Mills College California with Luciano Berio and Darius Milhaud. Remained in San Francisco for some time, devoting himself entirely to composition until in 1966 he returned to New York, where he set up his own ensemble, initially with only three other musicians but later expanded to 18, plus or minus.

Studied with Berio at Mills College in California. Says Reich, 'Serialism was just becoming known in this country and he [Berio] was a primary member of the team. So, being able to analyze Webern with him was very appropriate. At night I used to go to the Jazz Workshop where John Coltrane was playing–modal jazz. This was the most interesting music for me at that time—by day I was learning about what I did not want to do [serialism] but by night I was learning about something that I did want somehow to work into my life. Student composers were writing enormously complicated pieces…but they weren't being played. You had the feeling that no-one was hearing it in their heads; no-one was playing it on an instrument; it was just paper music. And then at night you see Coltrane playing—he just gets up and plays. So…I decided that I must play in my own pieces—whatever my limitations, I must become part of the ensemble.

Strongly influenced by ethnic music, as well as jazz.

Phasing

Reich had been using recordings of speech and everyday sounds. He'd been inspired by the poet William Carlos Williams, who had drawn inspiration from his local roots. He says he felt that Williams was saying to him, 'Go record the street. Go listen to your countrymen and get your music from the way they speak.'

Reich went down to San Francisco's Union Square in November 1964 to record a sermon by Brother Walter, a young black preacher, whose fiery sermons had become quite famous. Reich says he discovered 'that the most interesting music of all was made by lining up two identical tape loops in unison on different tape decks and letting them slowly go out of phase with each other' as his cheap tape decks each replayed at a slightly different speed. Later, when he acquired better machines, he would achieve the effect by pressing with his thumb on the supply reel of the tape providing the second channel.

This technique, playing identical looping samples together and letting the one go out of sync with the other, produces complex patterns, and is what is meant by 'phasing'. In the main section of Part I of 'It's Gonna Rain' a simple phasing process takes these words from unison through a complete cycle until they are in phase again. Another technique is what Reich called 'monophonic sampling. The loop is stereophonically separated 'exactly 180 degrees out of phase so that the word "it's" falls on top of "rain", more or less. Sampling each channel in synchronisation with the voice rhythm gives you "It's gonna..", "It's gonna…" over and over again. Speeding up the sampling will move the "It's gonna" inching into the "r" of "rain", then into "ain", "nn" and finally back to "It's gonna". The original tape also included the sound of a pigeon flapping its wings; I'm not sure if you hear it on this recording.

Clapping Music (1972)

There are two performers. Each claps out this same twelve-beat rhythm:

The first performer simply repeats the 'Basic Unit' again and again. In each 'phase' the second performer starts his Basic Unit one beat later than in the previous phase. After twelve phases the performers are in unison again.

Other works that are based on phasing are Piano Phase for two pianos and Violin Phase.

In Piano Phase you can hear the dualism of stasis and movement: one part repeats the basic pattern throughout the piece, while the second part accelerates, taking it out of phase with the first part. The second player starts one quaver further on after each iteration, so that, eventually, both players reach unison again.

In 1968 Reich laid out his ideas in an essay entitled 'Music as a Gradual Process'. Written in New Mexico in the summer of 1968 'to clarify for myself what I was doing':

• John Cage used processes…but the processes he used were compositional ones that could not be heard when the piece was performed…Similarly in serial music the series itself is seldom audible.
• What I'm interested in is a compositional process and a sounding music that are one and the same thing.
• I am interested in perceptible processes. I want to be able to hear the process happening throughout the sounding music.

Pendulum Music (August 1968, revised May 1973)

Three, four or more microphones are suspended from the ceiling or from microphone boom stands by their cables so that they all hang the same distance from the floor and are all free to swing with a pendular motion. Loudspeakers are then placed face upwards under the microphones, each connected to the microphone immediately above it. With the volume turned up, each loudspeaker will produce feedback when the microphone is directly above it. When the microphones are pulled back and released, their pendulum motion over the loudspeakers produces 'a series of feedback pulses…which will either be in unison or not depending on the gradually changing phase relations of the different mike pendulums. Performers then sit down to watch and listen to this process along with the rest of the audience.' As the momentum of the microphones' swinging decreases, so the phase relation of the feedback pulses constantly changes. The piece finishes 'sometime shortly after all mikes have come to rest and are feeding back a continuous tone, by performers pulling out the power cords of the amplifiers.

In 1970 Steve Reich went to Ghana to study drumming techniques with members of the Ghana Dance Ensemble and master drummer of the Ewe people, Gideon Alorwoye. Reich said 'He would play the bell pattern (which is the sort of timekeeper) and tell me when to come in with a pattern I'd already learned on the drum. It's one thing to learn the pattern and another to know when to play it.'

Reich was fascinated with the dense, extraordinarily complex rhythmic structure of West African music, which is built up of polyrhythms. Each player is assigned a unique rhythmic pattern that he repeats constantly. All the patterns are played simultaneously and each has a different starting point; they are held together by the glue of the chiming bell. Reich found that this music was not that different from what he was doing.

Four Organs (1970)

1968–69 were eventful years in the USA: assassinations of Robert Kennedy and Martin Luther King; the My Lai massacre in Vietnam; riots on university campuses. Reich conceived Four Organs which completed in January 1970. There's no phasing: its process consists of the gradual accumulation of a single chord. It takes about 20 minutes for the chord to grow in duration from a brief pulsation to a huge mass of sound, with no changes of pitch, timbre or harmony. Four keyboardists sit at electric organs and a fifth player shakes maracas to count time.

It was premiered at Boston's Symphony Hall in a programme that also included Mozart, Bartók and Liszt. But when the Boston SO brought it to Carnegie Hall in October 1971 there was a near riot. Michael Tilson Thomas, conducting, remembers threats being shouted, much booing - and also shouts of approval - and one woman ran up the aisle and banged her shoe on the stage yelling "Stop! Stop! I confess!"

Drumming (1971)

In Drumming there is a greater concern with timbre and texture of sound. Reich's ensemble expanded to use an extensive range of tuned percussion instruments: bongo drums, marimbas and glockenspiels. He added voices to the ensemble for the first time. He'd long admired the 'scat' singing of Ella Fitzgerald and was inspired to explore the possibilities of using voices wordlessly. He wrote 'while first playing the drums during the process of composition, I found myself sometimes singing with them, using my voice to imitate the sounds they made.' Men's voices were soon abandoned!

Music for 18 Musicians (1976)

This is a big step forward. The culmination of Reich's achievements in the works composed between 1965 and 1976. An hour long, longer than any previous work except Drumming. Largest group of musicians. For the first time he employs normal orchestral instruments.

• violin
• cello (originally was to be viola da gamba)
• two clarinets doubling bass clarinets
• three marimbas
• two xylophones
• vibraphone without motor (!)
• four pianos
• four women's voices

Some of these are amplified, but otherwise this is entirely acoustic - no electronics.

Reich wants to avoid having a conductor. Instead, the vibraphone plays aural cues at the end of each section, and at moments of structural change within each section as well. These are signals to the players, but also convey structure to listeners. I find myself listening and waiting for these, and when they occur I have a kind of 'goose-bump' feeling.

Here is a YouTube video of a complete performance of Music for 18 Musicians. It's not CD sound quality, but it's fascinating to see how this music is made.

1976 is a turning point, both for Steve Reich and the development of Minimalism. It will be similar for Philip Glass. One of the papers I found is entitled '1976 and All That: Minimalism and Post-Minimalism'.

After this, Steve Reich develops and diversifies - he's not a Minimalist any more. His Collected Works are 27 CDs; I've played extracts from the first five of them.

Alex Ross in his excellent book The Rest Is Noise wrote of Reich, 'Not since Wagner has a classical composer put so much of the outer world under his spell, whether or not the outer world knows it.'

Born in Baltimore on 31st January 1937. His father owned a small record shop. Glass grew up surrounded by music: 'hillbilly' music from West VA and Appalachians, commercially popular songs, some jazz, but also music of the European classical tradition. Began violin at age six, flute at age eight. Studied piano, harmony and composition with Louis Cheslock. Studied at the Julliard School where a colleague was Steve Reich. After this at age 25 he got a job as composer in residence working in public schools in Pittsburgh. He composed a lot of music in this job which he describes as 'straight, middle-of-the-road Americana'. At the end he'd composed over 70 pieces, some twenty of which had been published. Then he decided on further study, in Paris with Nadia Boulanger for two years. Increasing impatience with modernism led him to dismiss the musical avant-garde he found in Paris, centred around Pierre Boulez.

Theatre

Glass invited JoAnne Akalaitis, a theatre director and actress, to Paris and they married in 1965.

Jean-Louis Barrault's company put on new plays by Samuel Beckett and Jean Genet. Glass became involved with a collective group mostly of American emigres called Living Theater, and wrote music for some of their production. The group later moved to New York and took a new name, Mabou Mines.

Indian Music

Glass was hired to edit soundtrack material for an 'archetyicpally sixties hippy film' called Chappaqua. In the end Ravi Shankar composed the music for the film, but he needed an assistant to transcribe his work into Western notation for the French musicians, and to do some translating and conducting. Glass took the job and became very interested in Indian music as a consequence.

In 1966–67 he and his wife travelled extensively in Africa, Central Asia and India. In later years they made many more trips to India, exploring the whole sub-continent. The techniques of Indian classical music were important to Glass in the late 1960s, but they faded later on. His interest in the culture however continued, and he remains a practising Buddhist.

Keith Potter p. 263. 'It is clear that "there was a lot of interaction" between Reich and Glass for at least two years. But … a mixture of influences was making itself felt on Glass at this time. … Robert T. Jones concludes that "no one composer invented this music. It was an eruption of the times, an inevitability. It happened." '

In 1961 Glass saw La Monte Young's performance of Composition 1960 #1 (Draw a straight line and follow it) in Yoko Ono's loft. 'He had a pendulum hung to the ceiling, and he would swing the pendulum and wait until it came to a halt. And when it came to a halt he would draw a long white line. And he did that for about three hours. And I stayed for three hours; it was just a fabulous performance.' (Potter p. 262)

Visual arts

Various artists helped Glass with money and assisted in setting up contacts with the galleries, museums and arts festivals that proved to be much more interested in his music than were the main concert halls. (Potter p. 266)

Close association and friendship with the Minimalism artist, Robert Serra.

Strung Out

Took its name from the score of the piece, which was printed on twenty continuous pages which could be unfolded and 'strung out' around the performance space perhaps on music stands or pinned up on the walls. Part of the performance was to watch the violinist moving around the space. Example of the 'non-systematic' additive process prior to 1+1. A continuous string of fast quavers, for the most part. No bar lines - his tabla teacher's insistence that 'all notes are equal'.

1+1

1+1 is a quite clear example of Glass's 'additive process' technique. If you number the two 'units' as 1 and 2, the first of the three examples (labelled '1' in the image) comes out as 1+2, 1+2+2, 1+2+2+2, 1+2+2, 1+2 etc. What Glass refers to as 'regular arithmetic progression' in the score shown above. This rigorous approach to additive process is Glass's equivalent to Reich's notion of phasing. It served Glass well as his main structural technique for the better part of ten years.

Works where Glass further explores and develops additive processes:

• Two Pages (Feb 1969)
• Music in Fifths (June 1969)
• Music in Contrary Motion (July 1969)
• Music in Similar Motion (November 1969)

Music in Similar Motion possesses a subtlety, richness and depth foreign to its predecessors, which is the main reason why it is the composer's only work before Einstein On The Beach to remain in the repertoire of the Philip Glass Ensemble and to have been frequently performed by others.

• Music in Eight Parts (early 1970, abandoned)
• Music with Changing Parts (1973)
• Music in Twelve Parts

Music in Twelve Parts is the culmination of Glass's work written for his own ensemble between 1968 and 1974. The twelve movements each last between fifteen and twenty minutes, making a total performance time of over four hours.

From 1971 onwards Glass's reputation grows. He mounts concerts in his loft in Bleecker Street. First complete performance of Music in Twelve Parts at New York Town Hall on 1st June 1974. Reputation grows beyond New York. Starts his own record company, Chatham Square Productions, in 1971. Some other European labels release recordings of his music.

Einstein On The Beach

Glass becomes particularly popular in France. In 1973 Michel Guy invites the Glass Ensemble to play at the Festival d'Automne in Paris. The following year Guy becomes Secretary of State for Culture in the French government and commissions the work which did most to enhance Glass's reputation, the opera Einstein on the Beach. Premiered at the Avignon Theatre Festival on 25th July 1976; toured Europe with great success, followed by two performances the same year at the New York Met.

Here's a complete video performance of Einstein On The Beach in Paris on YouTube:

It's the first in a trilogy of operas which also includes Satyagraha and Akhnaten. The latter two are somewhat more conventionally operatic.

Einstein On The Beach is Glass's 1976 turning point. He is now successful and famous.

Glass went on to write much film music, including for Godfrey Reggio's extraordinary 1982 Koyaanisqatsi.

Post-minimalism was a term deployed by composer and Village Voice critic Kyle Gann to identify a new stream of compositional thought in the 1980s and 1990s. Composers picked up on the pulses and tonal harmonies of Riley, Reich and Glass and deployed them in written compositions that often subverted minimalist expectations. Some of these are: David Lang, Julia Wolfe and Michael Gordon (of the 'Bang on a Can' festivals), Jullius Eastman, Ingram Marshall, Ann Southam and many others.

A substantial figure is John Adams, sometimes called the 'fifth minimalist'. Ten years younger than the Big Four, really a different generation.

Alex Ross wrote: 'Minimalism gave Adams his individual voice. His defining move was to combine Reich-Glass repetition with the sprawling forms and grandiose orchestration of Wagner, Mahler and Sibelius.

Adams has spoken of Minimalism as 'the only really interesting important stylistic development in the past thirty years. As much as people would like to deny it, it is responsible for a revolution in music.'

Harmonielehre

Adams' Harmonielehre is a 40-minute symphonic work, its title taken from the textbook in which Schoenberg declared tonality was dead. Ian MacDonald, writing a rather harsh assessment of Minimalism in 1987 declared that Harmonielehre was 'Minimalism's first sign of real life…far and away the best thing the genre has produced.'

Note how it starts off in minimalist style, and about six minutes in a sweeping melody arises on the cellos and takes over the orchestra.

David Bowie was very aware of Reich's work in the 1970s. Bowie and Eno listened to Glass and Reich when they were working on Bowie's Low and Heroes albums. Bowie described Reich's work as 'a tone-track into the future'.

There are connections between (early 70s) disco and Minimalism. E.g.

Donna Summer Love to Love You Baby (1975)

When Philip Glass heard this he laughed and said 'That's exactly what we're doing!'

Little Fluffy Clouds (1990)

By English electronic group The Orb, who virtually invented the electronic genre known as 'ambient house'. They used a guitar sample from Reich's Electric Counterpoint. Reich said he was 'genuinely flattered' by their use and instructed the record company not to sue. There are voice samples from a BBC Radio 4 announcer and an interview with singer Ricki Lee Jones.

Listen to the Reich sample. Now play Little Fluffy Clouds and listen for the Reich sample in the background about 70 seconds in.

Brian Eno conceived what became ambient music when he was lying in bed recovering from an accident. He was listening to a tape of harp music which he couldn't quite hear properly together with the sound of rain on the window.

This is Eno's first ambient release Music for Airports:

As the Cold War ended, Westerners began to discover music from behind the Iron Curtain, including the so-called 'spiritual' or 'mystical' or even 'holy' minimalists. The holy minimalists of the 1980s and 1990s crafted austere, slow-moving music that was imbued with a sense of religious profundity.

They weren't influenced by the American Minimalists - they hadn't heard them because they hadn't heard any Western music from outside the Iron Curtain. But they arrived at somewhat similar techniques for similar reasons; principally a desire not to compose atonal, serial music.

Pärt interviewed in 1986:

Everyone who writes serial music thinks that the more complex the structure, the stronger and better it is. But that's not right: it's the other way round. Why is Webern's music so highly regarded…? Because it's so simple; disciplined and rigorous, but simple. … composers often think that because they think a lot they have something to say. They don't realise that they have almost nothing to say. Underneath all the complexity there is only a lack of wisdom and no truth.

Pärt arrived at a style he called 'tintinnabula', which means relating to bells.

This is the second movement of Tabula Rasa:

Górecki Symphony No. 3

In the spring of 1982 Paul Jamrozy of the British industrial music group Test Dept made a visit to Poland and happened upon a recording of Górecki's third symphony in a Warsaw record shop. He brought it back and during the mid-1980s the group used the symphony as a backdrop for video collages during their concerts to express sympathy with the Polish Solidarity movement. This was the first exposure of the piece to a substantial British audience. It later became a classical best-seller.

I've talked mostly about the Big Four. But there were many others. I will just mention some of the women:

• singer and light artist Marian Zazeela, who collaborated with La Monte Young, whom she married,
• composer Pauline Oliveros,
• dancer Meredith Monk,
• composer and singer Joan La Barbara, who joined Steve Reich's ensemble for three years, but then left to join Philip Glass's (which she found 'a lot more relaxed'),
• French composer Eliane Radigue.

I hope I've convinced you that there is real interest, value and pleasure to be found in Minimalist music.

I ended my talk where I began, by playing an extended extract from Music for 18 Musicians. In my opinion, and Tom Service's, it's one of the finest compositions of the last 50 years.