The sheer volume of Anthony Braxton’s output makes him one of the most daunting figures around — not just in " jazz, " a category he’s struggled with for his entire career, but in contemporary music, period. Braxton emerged from Chicago’s Association for the Advancement of Creative Musicians (AACM) in the late ’60s, working with Muhal Richard Abrams, Leo Smith, and the members of the Art Ensemble of Chicago, among others. Since then, he’s released upward of 130 recordings as leader or co-leader: solos, duos, quartets, larger " creative orchestra " ensembles, and a fair number on which he figures as non-performing composer. If anything, he’s stepped up production in recent years. A 1984 MacArthur " genius " grant enabled him to found his own Braxton House imprint, and an academic appointment at Wesleyan has supplied him with a stream of talented students and sidemen.

Anyone who makes a serious attempt to grasp this body of work risks never listening to anything else. So where should the interested but non-obsessed (what Braxton calls " friendly listeners " ) enter the maze? Well, there are unaccompanied-sax recitals like 19 (Solo) Compositions (New Albion, 1988), which display his alto mastery and chess master’s sense of strategy and structure in manageably monophonic chunks. Then there are the live documents of his longest-running quartet, with Marilyn Crispell, Mark Dresser, and Gerry Hemingway, which acted as a laboratory for his experiments with time and notation while still bearing a fleeting resemblance to jazz-as-we-know-it. Victoriaville (Victo, 1992), with its closing burn through Coltrane’s " Impressions, " is a good single-disc example.

Or you could simply plunge into the near-present. The just-released Four Compositions (GTM) 2000 (Delmark) is a studio quartet date with three recent students: pianist Kevin Uehlinger, double-bassist Keith Witty, and drummer Noah Schatz. Recorded in 2000, it’s significant in part as homecoming: this is Braxton’s first release since 1968 for the Chicago-based label that issued his first two albums. Otherwise, the disc is a representative slice of recent Braxtonia. That parenthetical " GTM " stands for " Ghost Trance Music, " which names a compositional strategy Braxton has been exploring since the mid ’90s. Like many of his ideas, the " Ghost Trance " pieces attempt to harness improvisers’ energies without the usual constraints of popular song form while stopping short of Albert Ayler–esque free blowing. (Braxton’s suspicion of the collective " freedom principle " made him an odd man out during the ’70s, when such ideas had a political meaning for many African-American musicians.)

The " GTM " pieces performed here — compositions 242 through 245, in Braxton’s taxonomy — begin with all four players working in unison, with a pronounced, almost marchlike pulse but no regularly emphasized downbeat. This martial feel is no accident; John Philip Sousa has been on Braxton’s list of admitted influences since the mid ’70s. Soon enough, instruments begin to veer away from the main road and then back — singly, in pairs, or even all at once, but always governed, at least implicitly, by the original pulse. It’s not hard to hear the individual instruments as passengers on separate subway lines that share the same first and last stations and cross paths at a few in between.

Does it swing? Not by most definitions — Schatz’s drumming seems especially constrained by the material. Is it as icily cerebral as Braxton’s reputation would suggest? Hardly. The less tightly plotted sections, which are ultimately the best reason for paying attention to this music, develop logically but inventively. Braxton, on a variety of reeds, threads his way through his self-imposed restrictions with ease, with Uehlinger’s piano as spotter for his acrobatics. Uehlinger is even better when he switches to melodica for much of " Composition 244, " employing squashed chord clusters that massage the beat rather than striking it head-on.

These performances don’t transcend the spiky GTM material as consistently as those on Six Compositions (GTM) 2001 (Ratascan), which was recorded later than the Delmark disc (with a different crop of Wesleyan associates) but released earlier. Six Compositions is a pricy four-CD, five-hour set on a poorly distributed specialist label accompanied by a tract-length booklet of Braxton’s famously impenetrable theoretical/mystical/political justifications of his music’s " tri-centric holistic system " that ends with the claim, " Theories are great but music is better. " But it’s probably the best next step for " friendly listeners " intrigued by Four Compositions. After that, you’ll have only 128 or so recordings to go.