“Personal style is fed by a multitude of of collective currents; we are the focus, the crossing point of intersecting trends, of colliding waves. Our own work, then, is a mirror of a great deal that hails from somewhere else.” Henri Pousseur gave that answer in 1983 to Bálint András Varga as part of Varga’s project to ask the same three questions to sixty-five then-contemporary composers [Google Book], and it serves as a good jumping-off point to get into his style. Pousseur unquestionably has a distinctive musical voice, but a core component of that voice is the bringing together of what would at first seem wholly incompatible elements.
Originally from Malmédy, Belgium, where he was born in 1929, Pousseur’s early years were rather tumultuous given the political developments that culminated in World War II — All of the English biographies I've been able to find skip over this period in his life entirely, but according to the French one on his website, he began his musical studies during the German occupation and managed to earn a spot in the Academy of Music in Liège after the war. From there he quickly fell in with the high modernists of the post-war avant-garde, working closely with Pierre Boulez, Karlheinz Stockhausen, and several other members of that circle. At some point, however, Pousseur and Boulez had a falling out — probably over Pousseur's use of aleatory and willingness to include tonal passages in his work — and they parted ways, which is hardly surprising given my general impression of Boulez’s autocratic, cliqueish tendencies.
Undaunted by the split, Pousseur continued to compose, teach, and write about music up until his death in 2009; he wrote numerous theoretical and philosophical treatises, some of which have been translated from French, as well as upwards of 200 compositions, among them an aleatoric piece for pre-recorded tape (as delightfully contradictory as that is) and a choose-your-own-adventure opera, Votre Faust. (It's seldom performed, since the company has to prepare several operas’ worth of material to allow the audience to decide the course of events, but practical considerations have never stopped a truly determined composer from doing what they want.)
Sadly, much as I would love to ramble on about three to seven hours’ worth of experimental mid-century opera, Votre Faust is not the piece we're focussing on today. Instead, we’re looking at a piece Pousseur wrote in 1973 in memoriam for Bruno Maderna, a friend and fellow composer: Vue sur les Jardins interdits (A View of the Forbidden Gardens), for saxophone quartet. If you're not generally a fan of sax quartets, don't run away just yet! This is a quartet that sounds relentlessly unlike any other sax quartet I know. It’s based off of “Herzlich tut mich erfreuen”, a chorale by the much earlier German composer Samuel Scheidt (1587 - 1654). (You can hear the chorale on this page, before a recording of an alternate version of the piece.)
Said chorale provides the musical material for the entire work, which Pousseur draws out by using his own process of “harmonic nets” — I haven’t been able to find a complete description of the technique, but it appears to revolve around finding shared intervalic relationships between horizontal melodic fragments and vertical harmonic sonorities. Whatever the specifics, the work opens with a barely audible whisper, the four saxophones clustering together with slow, tight, dissonant harmonies. Dim flutterings lurk in the background as the music gradually unfolds, like an elaborate mobile slowly springing to life after being packed flat for shipping. Gradually, too, the chords ease up on their early dissonance, the intervals expanding outwards into more consonant realms.
Eventually, after an interlude of fragmentary attempts at sustaining a musical line, the quartet embarks on a highly elaborated version of the chorale, interrupted by ecstatic flights of spiraling notes and rudely sustained extra tones. Perhaps this central passage is the forbidden garden of the title, the land of tonality and singable melodic lines marked out of bounds by prevailing mid-century compositional dogmas, but beautiful and enchanting all the same. As quickly as it sprang up, tho, the chorale quotation fades, dissolving back into a field of quiet, aching chords, full of sadness and longing. The intervals close back up, the opening dissonance returns, and the piece fades away with one last long final sigh.