An intent 60-odd persons attended an extraordinary performance Saturday night by trumpet virtuoso Lester Bowie and master drummer Phillip Wilson. A small audience indeed for two visinaries of black American music, but huge for d.c. space, local home of the cutting edge of the jazz avant-garde. The audience was of mixed gender and, with a few exceptions, young and white.

Utilizing no electronic gadgetry, the duo engaged in an improvisatory exchange that cast off the trappings of orthodox measure and tempo, harmony and melody. Initially, random choice and absence of structure seemed the order of the day, but as each extemporaneous composition got underway an inner logic and episodic organization took shape. Reciprocal communication was instantaneous and total, the one performer seeming to read the musical thoughts of the other.

Ripping off strings of fractional notes at murderous velocity to Wilson's machine-gun rim shots and pile-driving bass drum, Bowie's timbre would abruptly descend into nearly soundless breaths over a soft-as-tearing paper press roll from Wilson's snare. Pounding rain on the cymbals punctuated by cracks of thunder from the deep tom-tom would mingle with the horn's emotion-tangled moans, whimpers, screams and phrases in "legitimate" tone.

A vistor to these shores from France commented on the opening number, "The first thing they made was for me very moving." Its companion piece in the opening set, a tongue-in-cheek pastiche of military motifs including "Reveille," "Taps" and a halting march cadence, was a tour de force of wry wit.

A space-age sound that came up out of the jazz tradition.