Pierre Boulez: Visionary composer and conductor who transformed the face of 20th-century classical music

The death of Pierre Boulez marks the end of a compositional era. From as early as 1946 – when he stormed on to the musical scene fresh from Messiaen's class at the Paris Conservatoire – his personality and ideas exerted almost as profound an influence on the second half of the 20th Century as did those of the Viennese on the first.

Aware even then of his position at a crossroads of musical history, he set out intentionally to rival and to transcend the achievements of his forebears. He succeeded (to an extent that could scarcely have been predicted at the time) in encouraging a whole generation of composers to endorse his attempt to establish the inclusive grammar of an atonal soundworld, sufficient to provide the musical foundations for the next 50 years.

Despite the stylistic backlash represented by the various "isms" of the 1970s and 80s, his (self-) disciplinary concepts remain an essential ingredient of compositional awareness – even if his own work may be judged to have suffered as a result of his single-minded determination to change the course of Western musical history.

Born in 1925 in Montbrison in the Loire department of central France, he lived through the Nazi occupation of his homeland, and came relatively late to full time musical education. Yielding to family pressure to complete a foundation course in mathematics, he was 19 before he began his two-year studentship with Messiaen – but his prodigious intellectual grasp, even then, enabled him to absorb ideas and information at astonishing speed.

From being a precocious adolescent, he was to emerge as the most gifted and original composer of his generation before he was 25: composed in quick succession, five works (the Sonatina for flute and piano, two piano Sonatas, and two vocal cantatas, Le Visage nuptial and Le Soleil des eaux) were to establish his fame almost overnight. But they also comprised an act that was hard to follow. Much like the instrumental prodigy, who acquires technical virtuosity without understanding the problems experienced by others, so Boulez was then forced to stop, to take stock, and to find the means of forging a language that would assure his compositional future: as with all prodigies, it was only then that problems arose – as reasoned considerations began to take over from the instinctive invention of the early years.

He was also beset by the problems endemic to a generation growing up in a post-war world where everything – in the arts no less than in other respects – seemed in need of reconstruction: these were times which were eventually to destroy much of the gilded youth of the Darmstadt years, leaving them creatively stifled as a result of so much theoretical effort. That Boulez himself fought his way through the crisis by finding entrepreneurial tasks to absorb his musical energies and ease his compositional depression – without equivocation or any dilution of his youthful ideals – is both evidence of his unyielding sense of purpose and one of the reasons for the enduring impression he has left.

His discovery, in the mid-1950s, of Stéphane Mallarmé, the poet haunted by fear of a decline in creativity, came at a moment when his own inability to recapture the inspiration of his early years was at its height – providing much-needed reassurance and endorsing the concept of the unfinished work. Although in the end this was to prove no more beneficial for Boulez than for Mallarmé, at least it encouraged him to proceed during the barren years, bridging the unselfconscious clan of the leader of the avant garde and the more consciously acquired reputation of the father figure to succeeding generations.

These were years of sometimes fruitless struggle, during which he was sustained only by the example of Mallarmé's magnificent but ultimately sterile project of the unfinished "Livre". In the event, it is perhaps ironic that the only completed work to emerge from this period was Pli selon pli (1957-58) – Boulez's musical portrait of Mallarmé.

Despite the jet-setting, cosmopolitan lifestyle of his middle years, Boulez remained the archetypal Frenchman. Like Debussy before him, he was undoubtedly spurred on by a resolve to withstand the ever-threatening supremacy of Austro-German musical culture again beginning to arise from the devastation left by the Second World War. His wide-ranging conducting repertoire could not conceal the fact that he never really understood the harmonic tensions inherent in the music of the diatonic past (and of German music in particular) – a defect that was itself a positive characteristic of his deep-rooted Frenchness. He nevertheless transformed performing attitudes and standards as radically as he had earlier transformed compositional ones.

Self-taught as a conductor, he evolved a technique and a manner of working far removed from the notion of the domineering maestro figure consequently banished for ever in generations succeeding his own.

Always taking to the podium without a baton, Boulez conducted many of the greatest orchestras. The 1970s were particularly fruitful: he was musical adviser to the Cleveland Orchestra from 1970-72; chief conductor of the BBC Symphony Orchestra from 1971-75; and music director of the New York Philharmonic from 1971-77.

This latter post produced some of his most notable, and controversial, performances. Some members of the Philharmonic were reportedly uncomfortable with Boulez's insistence on a modern repertoire (Berg, Debussy, Mahler, Stravinsky, Bartók...) – and presumably must have been even more so when, in 1973, he replaced their chairs with rugs and scatter cushions – more in keeping with the city's prevailing hippie scene.

Impatient with hypocrisy or self-importance in others, he was generous to those he perceived as talented; secure in the strength of his own abilities, he remained a modest man, reluctant to promote his own work – even though his achievements in the sphere of performance made others hesitate to take up the baton on his behalf.

Whether or not his own music will, in the long run, be valued for itself as opposed to its place in musical history, only time will tell: the astonishingly self-assured brilliance of the works of the 1940s will surely guarantee them an enduring place in the repertoire, even if the more effortfully contrived music of the late-1950s and 60s may be considered to occupy a fringe position as in part somewhat ungainly curiosities.

His later involvement with yet another attempt to change the course of events, by bringing electronic music under his personal jurisdiction at IRCAM (the music and science research institute next to the Centre Pompidou in Paris) seemed finally to spark off a new period of creativity – despite the time-consuming effort involved in founding, funding, and organising an independently conceived project on a scale and with an influence till then unprecedented. Then-president Georges Pompidou had asked Boulez to found the institution in 1970; it finally opened, under Boulez's charge, in 1977.

He had additionally to learn and to digest the technical possibilities of his own brain child – no easy task for a man already approaching late middle age, and with much else on his mind. In other words, he had himself to become a student of his own institution in order to validate its existence: just as earlier he had had to compose the works to "justify" his written grammar (as pronounced in Boulez on Music Today, 1971), so now he had to produce the musical justification of his determination to encompass and to extend the electronic medium.

What might have been a mere exercise in the new computer-based techniques turned out to be the major inspiration of his latter years: scored for instruments and electro-acoustic equipment, Répons, completed in 1984, stands as a monument to late 20th-century achievement.

Outside of the world of modern classical music, he found a kindred, experimental spirit in the form of the maverick rock musician Frank Zappa. In 1984, the pair collaborated – and Boulez conducted the Ensemble InterContemporain in three of Zappa's works.

Boulez continued to conduct and compose until the final years of his life, and remained a steadfast champion of modern music. In 2004, with Michael Haefliger, he founded the Lucerne Festival Academy, a summer orchestral institute for young musicians with a focus on the music of this century, and the last. In 2008, he helmed a memorable concert of the music of Janacek for the BBC Proms at the Royal Albert Hall, and in 2010 he completed his 15-year, multi-orchestra Mahler cycle for Deutsche Grammophon. Among countless awards, he was the recipient of 26 Grammys.

The sheer energy of the man was indeed awe-inspiring, often invoking jealousy from those who would have liked to – but who did not – emulate him. In the end, however, admiration prevailed (if sometimes grudgingly), both for his matchless talents and for the extraordinary manner in which he succeeded in changing the face of 20th-century European music. To his friends he was a man both loved for his occasional flashes of reciprocal warmth and pitied for the loneliness resulting from his almost wilful determination to remain aloof. To all who knew him he was, and will remain, quite unforgettable.

Pierre Boulez, composer and conductor: born Montbrison, France 26 March 1925; died Baden-Baden, Germany 5 January 2016.

Susan Bradshaw died in 2005.