A musician’s “voice” is not simply a metaphor. No two creative instrumentalists ever sound quite alike. Even on the piano, the touch and attack of Ashkenazy are immediately distinguishable from those of Brendel or Gould. And so it is, right through the orchestra, even if it takes a certain refinement of perception to tell one oboe soloist from another.

The saxophone represents a special case. It is an instrument that, for reasons of design and history, almost entirely depends on the personality of the player. The peculiarities of its manufacture–the saxophone family is all conical-bored and overblows at the octave–and its emergence at a time when the basic language of the classical instrumentarium was well established, bequeathed it a curiously marginal status. Despite the enthusiasm of Hector Berlioz and occasional appearances in the nineteenth-century orchestra, the saxophone’s apparent destiny was to play a down-market role in vernacular music: marching bands, pit orchestras, bal musette and, of course, jazz.

All instruments–Strads, Gazzelloni’s titanium flute–have “wolf tones,” places on the instrument where the specific design or that particular instrument’s history requires the player to alter technique to keep it in pitch. The saxophone has nothing but. A basic scale played on a tenor saxophone has less character than those same notes written on a stave, and yet most jazz fans will identify the great saxophonists from the shortest phrase or measure. Their voices are as distinctive as the whorls and loops of a fingerprint, or the particular cadence and timbre of a speaking voice.

Who would not immediately recognize Johnny Hodges, that high, erotic wail that rose out of Duke Ellington’s ensembles; or Sonny Rollins’s muscular street orator’s discourse; or Lester Young’s wounded grace; or John Coltrane’s hard-toned intensity? The list goes on: Sidney Bechet, Coleman Hawkins, Chu Berry, Warne Marsh and Lee Konitz, Paul Desmond, Ornette Coleman, Steve Lacy, Anthony Braxton, Evan Parker, Jan Garbarek–all of them possessed of a rich idiolect. If Charlie Parker had lost his passport, and he was erratic enough to do just that, a single tone on his horn would have been enough to get him past immigration.

Among saxophonists, Roscoe Mitchell is an anomaly. Although he is one of the most innovative and important of the current senior generation, few could describe with any confidence what is distinctive about Mitchell’s “voice” or reliably recognize it in any of its multifarious contexts. Of course, that may be part of the problem. Mitchell’s dogged commitment to experiment has led him into projects far removed from the conventional jazz combo. Or it may be that, since he has spent a large proportion of his career as part of the most successful “avant-garde” jazz group of modern times, the Art Ensemble of Chicago (AEC), we hear him only as part of an ensemble voice. Or it may be that because of Mitchell’s dedication to multi-instrumentalism, playing a full range of horns from the soprano to the bass saxophones, as well as flutes and noncanonical instruments, we are liable to be misled by an unfamiliar tonality or sound color. Yet Anthony Braxton, another multi-instrumentalist with a very similar background and philosophy, always sounds like himself whether playing alto saxophone, the unfeasibly large contrabass or, indeed, any of the more exotic varieties in between.

The enigma is relatively easily resolved. Mitchell’s roots in jazz are deep, but he is also profoundly versed in European art music, and particularly the atonal music of the early twentieth century. In fact, his interests in music seem to have no boundaries. Though he has worked in free improvisation–hewing to no predetermined parameters and often playing “little instruments” of ad hoc design–and though his recorded and public work frequently alludes to the blues, field hollers, folk narratives and even standard thirty-two-bar song structure, his real interest lies in a little-understood nexus of two apparently contradictory approaches to music. If anything can be read into the trajectory of a recording career, it’s no accident that Mitchell’s first record, released in 1966 on Delmark, is called Sound and that his latest, a return to the European ECM label, is Composition/Improvisation Nos. 1, 2, & 3.

We are not properly prepared to detect his “voice” if we listen for it only in the overtones of his saxophones. To hear Mitchell, it’s necessary to understand that his work is premised on improvisation as a form of composition and that the usual sharp distinction between the two processes has been suspended. His goal is to be a “super-musician” to whom matters of style, form, instrumentality, even personality have become irrelevant.

Roscoe Mitchell was born in Chicago in the summer of 1940. He first took up the clarinet at the age of 12. While serving in the Army in Germany, he studied with the first clarinet of the Heidelberg Symphony and played in a band with tenor saxophonist Albert Ayler. Returning to Chicago in 1961, Mitchell found himself in a scene in which the old communitarian spirit had begun to acquire a new political edge, sharpened on one side by the civil rights movement, on the other by the simple contingency of making a living in a club scene where rule changes had made larger group performance commercially unviable.

Mitchell was soon in contact with pianist and composer Muhal Richard Abrams, a powerful catalyst on the Chicago scene. He had been playing bebop with a group from Wilson College that included Braxton, fellow saxophonist Henry Threadgill, bassist Malachi Favors and saxophonist Joseph Jarman (the latter two being future AEC members). From Abrams he got invaluable encouragement, not least to write as much and in as many varied styles as possible. He began to work with the pianist’s rehearsal group, the Experimental Band. Mitchell took from the experience an understanding that the production of sound was, in Western music, reserved for an extremely hierarchical group of objects–pianos, violins, trumpets, kettle drums–when in fact sound, and therefore music, could be produced by almost any means. Also, the experience of playing in what was essentially a workshop allowed Mitchell to reconsider the relationship between music-making in pure form and public performance. The absence of an audience made crowd-pleasing histrionics meaningless. It also made silence less uncomfortable. These were ideas that had recently been explored by alto saxophonist Ornette Coleman, a Texan maverick whose own struggle to be heard had led him to explore the use of silence.

The opening track of Mitchell’s first recording was a tribute to “Ornette.” The music presented on Sound was very different from that of the New York avant-garde, whose signature features were intensity of expression and individualistic soloing. By contrast, Sound seemed to arise from a collective philosophy, alternating periods of dynamic playing with relative silence, incorporating sonorities not usually associated with modern or avant-garde jazz–cello, harmonica, recorder–as well as all the informal instruments and toys deployed by group members.

By the time Sound was released, Mitchell was a member of the Association for the Advancement of Creative Musicians (AACM), a nonprofit body founded by Abrams with pianist Jodie Christian, drummer Steve McCall and composer Phil Cohran. At a time when there was severe economic pressure on players, it made surprisingly little difference how unorthodox their work was: little work either way, beyond what was happening under Abrams’s experimental umbrella.

The Mitchell sextet, which was the first AACM group to make a record, evolved into the Roscoe Mitchell Art Ensemble and subsequently into the Art Ensemble, with a personnel including trumpeter Lester Bowie and Malachi Favors on bass. Other sextet players moved on. Joseph Jarman joined as a second saxophonist. Percussionist Alvin Fiedler was briefly replaced by Phillip Wilson, but it was as a drummerless quartet that the group left the United States for France in 1969.

The Art Ensemble of Chicago–the location was added to give the group a more specific identity in Europe–was an immediate success there. Perversely, it was easier in Europe to assert the African origins of jazz, in the sense of privileging rhythm rather than harmony or even melody, and in restoring a concept of music as social ritual. Though Mitchell (and Bowie) seemed to stand somewhat apart from the group’s more theatrical dimension–appearing onstage in colorful costumes and face paint–the AEC’s stage show was in its way as definitive as that of the Sun Ra Arkestra, and similarly deceptive. It was a clever stratagem, with obvious audience appeal, but ironically it also allowed the musicians to develop their advanced compositional ideas more privately–behind the masks, as it were. At first the four members played small percussion, thereby creating rhythmic backgrounds for the group that were very different from the heavy, regular counts provided by a swing or bebop drummer. But it was in France that the group met Don Moye (later Famoudou), who joined as percussionist, thus completing the familiar AEC lineup.

All the while, individual members continued to pursue creative paths beyond the AEC. Jarman made two records for the Chicago-based Delmark label, which had released Sound and later put out Mitchell records such as Hey Donald and Sound Songs (both 1994). Bowie began his solo recording career at the same time as Mitchell, with Numbers 1 & 2 on Nessa. This was the imprint that in 1977, six years after the AEC’s return from Europe, released Mitchell’s classic Nonaah, a series of performances with group members and others, also duos and saxophone solos similar to those on the earlier Solo Saxophone Concerts (Sackville, 1974). Here one finds Mitchell exploring extremes of tonality and timbre, playing soprano, alto, tenor and bass saxophones on the earlier disc, and on the later one in an ensemble setting that includes Anthony Braxton on the impossibly pitched sopranino. At other times in his recording career, Mitchell has also played baritone saxophone and the now rarely used C-melody saxophone, an attempt to provide a horn in concert pitch rather than the more familiar E flat and B flat of the saxophone family.

How securely Mitchell can be defined as an avant-garde artist is open to question. To be sure, the music on the solo saxophone concerts is radical and stripped down–Braxton is mistakenly given sole credit for pioneering this area of inquiry with his 1968 For Alto–but the non-AEC Mitchell discography is far more varied and tuneful than the shorthand version might suggest. Alongside the more abstract-sounding sets–Four Compositions, Two Improvisations, Solo x 3, Sound and Space Ensembles–it includes such delights as Snurdy McGurdy and Her Dancin’ Shoes, which neither threaten nor deliver music of a fearsome sort; in fact, no fewer than five Mitchell records include “song” or “dance” in their titles, while his ECM solo debut in 1999 was Nine to Get Ready!

The blue-chip European label was as logical a destination for a composer of Mitchell’s Modernist tendencies as Delmark, Sackville and Nessa had been for a player of his deeply rooted traditionalism. For a large part of his career, he has been dependent on transatlantic imprints, particularly the Italian Black Saint, to put out his work. Returning to the United States in 1971, the AEC found itself in an environment where jazz had been largely eclipsed by pop and rock, and where the political tremors of the late ’60s had led to a substantial backlash against black militancy and nationalism. Again, Mitchell’s and his colleagues’ reaction was neither quietist nor compromised, but neither was it a wholesale involvement with the political scene. In 1974 Mitchell moved to East Lansing, Michigan, where he also formed the significantly named Creative Arts Collective and an associated group called the Sound Ensemble. These were further steps on Mitchell’s long journey toward composition based directly on the spontaneity of improvised music.

The 1980s were divided between AEC duties and recordings for Black Saint, which saw Mitchell working a sometimes precarious line between advanced composition techniques and vernacular forms, a divide in his work that sometimes blurred and confused his public profile. Working in Michigan had made available to him the resources of Michigan State University and particularly the music and performance schools. Mitchell made contact with new-music composer-performers like accordionist Pauline Oliveros, pioneer of Deep Listening, and the vocalist Thomas Buckner. Oliveros’s use of an essentially vernacular instrument to develop avant-garde ideas intrigued Mitchell, as did Buckner’s confident appropriation of a huge range of singing styles, canonical and noncanonical. Those lessons are beautifully expressed in the 1999 Delmark album In Walked Buckner, dedicated to but not actually featuring the singer.

Mitchell and Buckner had, by this time, worked together very fruitfully as Space, in which they were joined by multi-instrumentalist Gerald Oshita, who used such unlikely horns as the Conn-o-sax and the contrabass sarrusophone. For a musician as interested in the placement of note choices as Mitchell was and is, the ability to work in proximity to such extremes of pitch and with Buckner’s unconventional sounds was extremely liberating. A still later group was called Note Factory, a clear indication that for all the rhythmic democracy of the AEC, Mitchell was increasingly thinking in terms of pitches and scales, adapting the fast scalar improvisation that is so fitting for the saxophone to more elaborate constructions. Typically, though, he has tried to avoid imprisoning himself in vertical harmony or in any approach that requires a strictly hierarchical understanding of pitches. As recently as 2004, on the Mutable disc Solo 3, he released improv/compositions that make use of a “percussion cage” that combines “found” and real percussion instruments (and maybe name checks John Cage as well).

The only area of contemporary music Mitchell did not seem to have explored was the field of electronics. In that, he resembled the somewhat younger English saxophonist Evan Parker, whose solo saxophone explorations (mostly on soprano) were increasingly devoted to finding overtone series and fields of great mathematical precision and expressive intensity. Fifteen years ago, though, Parker began to explore electro-acoustic approaches, partly through a brief collaboration with Danish trio Ghost-in-the-Machine and subsequently through his own Electro-Acoustic Ensemble, which has now released four records with ECM.

In the autumn of 2004, Parker and Mitchell came together in a concert hall in Munich to record a grouping that involved members of the Englishman’s ensemble–including bassist Barry Guy and violinist Philipp Wachsmann–and members of Note Factory and others, under the ad hoc title The Transatlantic Ensemble. The immediate feel of Composition/Improvisation Nos. 1, 2, & 3 is very much of a classical group, with strings, tymps and piano, generating a sound-world that makes one think first of European art music. Indeed, there is little about the longish opening track that would lead one to feel that improvisation plays any substantial part in this performance or that jazz is in any way part of its genetic make-up. Intriguingly, the first inkling that this is not the case comes toward the end of the short second section, when percussionists Tani Tabbal and Paul Lytton engage in the first of several instrumental dialogues that punctuate this remarkable record.

Mitchell plays soprano saxophone throughout, while Parker deploys his tenor, yet what defines this music most clearly as the American’s is not the sound of his horn but something about the way the music organizes itself into periods of intense activity bracketed by silence, duos breaking out of the ensemble in a spirit that veers between conversation and contention and in contexts that are alternately ordered and chaotic, or seemingly so. The sequence of “movements,” nine in all, and the title reference to three parts don’t quite seem to square unless one checks the sleeve frequently. That is why the title is not given as Composition & Improvisation (as if a set of themes and variations) but with a slash that more or less suspends any fundamental distinction between the two. As with much of Mitchell’s work, the delivery is mostly rather quiet and unemphatic, with a tendency to dwell not just on exact pitchings but also on the precise tone color of particular sounds. Pianist Craig Taborn’s role is fascinating. At some moments, he seems to be articulating some approximate tonal center for the music, some gravitational point of reference that never quite manages to resist the centrifugal energy of the strings and horns; at others, he is the archetypal pianist-as-percussionist, banging out sharp attacks that are more reminiscent of Cecil Taylor’s famous “eighty-eight tuned drums” definition than most of the work lazily and misleadingly attributed to Taylor’s influence.

The long movement “III” moves into something like “free jazz,” but while there is considerable exhilaration in the playing, this is arguably the least typical and least successful aspect of the performance. After some more short sequences, there are two extended movements (“VII/VIII”) in which the integration of elements seems more complete though not subject to any discernible logic or determination. The coda is deliciously ambiguous. Far from reaching a climax, the sequence dissolves into a shimmer, as if some tiny subset of the whole cosmological process has gone into reverse, solids turning to gas, orbits no longer regular or fixed, location and velocity uncertain. Nothing in the whole canon of twentieth-century Western art music conveys so much satisfying mystery.

Like most exploratory artists, Mitchell prefers the forward glance to the retrospective and fears repeating himself. But even in this most formally conceived of performances, he has managed to bring together elements that have been part of his work from the beginning: pure sound, sound that obeys or resists hierarchical organization, rhythm as fundamental rather than embellishment, improvisation not as a gone-in-the-air end in itself but as an inseparable element of the composition process, composition as a dynamic rather than an ossifying procedure, passion, cerebral abstraction, a sense that musical “meaning” is always subject to slippage. Multi-instrumentalism has only enlarged and enhanced his playing personality rather than obscured it; at base, Mitchell’s only “instrument” is sound itself. Over the years, he has followed a doggedly individual track, whether within the joyous exuberance and discipline of the Art Ensemble of Chicago, out on his own as a solo saxophonist on an instrument only ever meant to play low accompaniments, as a song-based bandleader, as a “classical” composer, whether playing sounds as dry and delicate as those he conjures from his percussion cage or hollering a rap on “You Wastin’ My Time.”

These are the qualities that make him Roscoe Mitchell, but still indefinable. One sympathizes with anyone charged with pinning down in a few words what he sounds like, which is why more than a few reference books and critical articles fall back on quick formulations like “multi-instrumentalist” or “avant-garde” or “AACM musician” or even “member of the Art Ensemble of Chicago.” His “voice” can’t be detected in a single saxophone phrase or timbre, but that is not to say it can’t be found. It is present and utterly distinctive in everything he has done over four decades.