Minimalism at 50: how less became more

Minimalism won the battle for stylistic supremacy in the 20th and 21st centuries – but became something its composers never intended
Steve Reich and five bearded colleagues playing vibraphones
Less is more, except in beards ... Steve Reich and colleagues in the early 1980s. Photograph: Bernard Gotfryd/Getty

Minimalism is 50 years old this month. Today, the 20th century's most successful musical "ism" has got its repetitive, beat-based tentacles in every part of musical culture, from film scores to pop albums, jazz riffs to contemporary classical soundscapes, and a musical movement that began in lofts, galleries and collective spaces in New York and San Francisco in the 1960s has become an international phenomenon. If its big idea is that less is more, then minimalism has done more with less than pretty well any other musical movement in history.

But since you can hear debts to similar ideas in music from composers as different as Björk, Radiohead, Arvo Pärt, Louis Andriessen and Terry Riley, you could say minimalism died a long time ago, and what's left is a musical maximalism.

This week's festival with the piano-playing Labèque sisters at London's Kings Place invites us to listen to music from John Cage to Steve Reich, Glenn Branca to Brian Eno, Michael Nyman (who first coined the term "minimalism" in 1968) to the Who, and hear the cross-cultural connections. But I think what the 50-year history (well, 50-ish: the movement's year zero is pretty arbitrary – what could be more minimalist than John Cage's 4'33'', written nearly 60 years ago?) tells us is how what started as an ideology of purity of process, of music stripped back to its essentials, has become a grab-bag of ideas composers draw on when they want to create hallucinogenic textures of pulse-based sensuality, or to lull us into supplication with holy reverie.

But that's all a long way from whatever it was minimalism meant to the composers who were at its vanguard in the 60s. The big four back then, as now, were Terry Riley, La Monte Young, Steve Reich and Philip Glass. None of them, it is worth pointing out, has ever fully embraced the term "minimalism", and the seeds of how differently the minimalist impulse would be taken up by later composers are already there in the huge aesthetic and temperamental gulfs that separate Riley's music from Reich's, or Glass's from Young's. All are now in their mid-70s: Riley is a devotee of Indian philosophy, Young lives according to a 27-hour day in his Dream-House in downtown New York, Glass writes symphonies and film scores, and Reich, the most revered of the quartet, continues to plough his furrow of pulses, phases and rhythmic richness.

But 50 years ago, all four did have something in common: a commitment to exploring the base materials of music with forensic, analytical detail. Reich's early works, such as the tape piece It's Gonna Rain and Piano Phase, for two pianists, that the Labèques played in yesterday's opening concert, are about a single, obsessively pursued idea. Reich's revolution was to loop different versions of the same material at different speeds against itself. Written down here, it sounds like a tortuous, solipsistic process – but it's really pretty simple to hear. In It's Gonna Rain, the voice of a Pentecostal preacher is looped at gradually different speeds, creating a sumptuous sonic texture, and in Piano Phase the pianists have to move in and out of phase with one another, subtly shifting from one semiquaver of a melodic pattern to the next. The effect is the sonic equivalent of slowly turning a kaleidoscope as the music comes in and out of focus. If you haven't heard it yet, do it now – it's a thrilling, essential listen.

But there's something else in early Reich, Glass and Riley, too – an insistence on returning music to the roots that all three composers felt European modernisms, such as serialism, had left behind: melody, modality and rhythm. Riley's In C puts all of that together in a piece that remains a masterpiece of compression, one of the great musical proofs of how less really can be more. From 53 tiny cells of musical material – the whole score fits on one page – Riley allows his performers to create an unpredictable, ever-changing tapestry of sound as the musicians (of which there can be any number) move from one bar to the next. In C is a game-changer not just for minimalism but for music history. Glass wasn't far behind, either, in such pieces as Music With Changing Parts, while Young created music of slowly shifting chords and harmonies, extending the minimalist idea into larger, longer spheres of time and being.

Yet what happened in the generation after these composers had started to stretch the definition of minimalism to breaking point? Even John Adams, often called a second-generation minimalist, only uses the surfaces of the rhythms and energies of the pioneering minimalist quartet of composers, creating the huge, pumped-up pounding of his opera Nixon in China or his orchestral piece Harmonielehre. This is minimalism on steroids, in which Adams is as indebted to the European late Romantics Mahler and Schoenberg as he is to Reich.

Once minimalism became just another style for composers to use, it stopped being minimalist in any meaningful aesthetic sense. Such composers as David Lang or Michael Gordon, or any of the Bang on a Can group of New York-based post-minimalists, couldn't have written their music without Glass; but equally, they couldn't have written it without the influence of rock. The impulse for any composer who uses minimalism as a style today – whether you're Thom Yorke or Nico Muhly – is the diametrical opposite of what Reich and Riley were up to half a century ago. Stylistic free-for-all has replaced forensic, monomaniacal obsession.

Maybe that's no bad thing. The 50 Years of Minimalism concerts really reflect a history of how a single-minded ideology became an aesthetic, then a style, then simply one option among hundreds for composers to choose from. Minimalism won the battle for stylistic supremacy in the 20th and 21st centuries, no question, but where once less was more, it's a maxed-out "more" that now rules the roost. More or less …

50 Years of Minimalism continues at Kings Place, London until 26 November.