A performer whose work systematically crosses categorical boundaries and causes critical dissension is an original. James Blood Ulmer certainly fits that description, and his music is nothing if not idiosyncratic.

Ulmer's compositions have been classified as punk, jazz, funk and new wave -- and all of that is correct. He has been accused of diluting funk's purity with more catholic -- and profitable -- musical elements, and extolled as "the most innovative guitarist since Hendrix"; but neither of these views is quite right.

A protege of Ornette Coleman, Ulmer comes by his fusion and diffusion quite naturally. He began his musical career at seven as a member of the Southern Sons, a traveling gospel group. Later, he learned guitar and began playing the rhythm-and-blues circuit, focusing on Detroit and Philadelphia.

Not surprisingly, Ulmer has assimilated all these forms, and "Free Lancing," his first album for a major label, is a rich and rhythmic blend of American music history and futuristic funk.

Ulmer may well subscribe to Coleman's "harmolodic" school of jazz thought, but it's rhythm, rather than melodic intervals, that strikes the listener first. Not the conventional patterns that rely on fixed downbeats and evenly partitioned measures: Though Ulmer uses his guitar primarily as a rhythmic instrument, he comes as close as possible to free-form jazz without abandoning harmonic structure; he gives greater consideration to the aspect of movement.

Yet his music bears little resemblance to the experimentalist guitar work of, say, John McLaughlin. It contains neither McLaughlin's unmetered, rapid-fire scale-running nor the thoughtful free-form lyricism of Pat Metheny. The best way to describe this sound is to say that it percolates.

The task of fleshing out melody and harmony fall to bass and percussion, largely handled on "Free Lancing" by Amin Ali and G. Calvin Weston, so attuned to Ulmer's thematic ideas that the songs amount more to architecture than mere structure. Occasionally a track is punctuated by horns and backing vocals as well, but the essential makeup is Ulmer's mobile guitar anchored by full-bottomed bass and accented by inventive drumming.

To this basic outlay is added a suitable backdrop from Ulmer's varied repertoire: Latinish on "Night Lover," punkish and candid on "Timeless," big-band on "High Time," funky and gospel on "Pleasure Control" and "Where Did All the Girls Come From?" To his credit, Ulmer does not seem to use these forms as mere thematic manipulation or window-dressing, but as real complements to the work at hand; his integrity of choice and commitment never come into question.

Such vocals that exist on "Free Lancing" are also an extension of the prevailing musical idea. Ulmer's vocal style is more of a distracted mumble than actual singing, yet on such songs as "Pleasure Control" he evokes James Brown and Jimi Hendrix at the same time, putting still another angle on his asymmetric funk.

This is not "dinner jazz" or background music. It seems constantly to be probing, moving, asking questions, and it requires the thoughtful attention of its audience. Whether Ulmer will establish himself as a premier American artist remains to be seen, but he will certainly find himself in the vanguard of popular music's new/old emphasis on rhythmic forms and formlessness.

It should be remembered that Ulmer is not a funkster by trade, or at least no more so than he is a jazzman or a punk guitarist; in short, he's no purist. And, though his is a truly original and explorational style, it lacks, alas, the sensuousness that was as much a part of Hendrix' signature as his innovative technique.

Of course, the best way to categorize Ulmer is to listen to the album.

THE ALBUM -- James Blood Ulmer, "Free Lancing," Columbia ARC 37493.

THE SHOW -- Sunday at the 9:30 Club.