The final two nights of the Sixth Annual D.C. Loft Jazz Festival at d.c. space were as comprehensive a summary of contemporary sounds as one could reasonably expect from a set apiece by four groups. And making for some telling contrasts were the juxtaposition Friday of Ron Holloway's hard-hitting neo-bop quintet with the serenity of the East-West Quartet, and Saturday's pairing of the relaxed and structured be-bop of Webster Young's combo with the free-form urgency of saxophonist Jimmy Lyons, bassist Hayes Burnett and drummer Nasar Abadey.

Holloway's group dedicated its set to trumpeter Lee Morgan, whose murder in 1972 aborted the career of one of the most promising young jazz artists of the time. Morgan's "Trapped" featured some joyous tenor sax by the leader and an incisive solo by trumpeter Chris Battistone. On "Ca-lee-so," another Morgan tune, the piano of Michael Bearden lent the calypso rhythm a foot-stomping buoyancy, coaxed along by James King's steady bass and the muscle of Mike Smith's drums. Holloway's a cappella summation of the tradition that touched on Ellington, the blues, atonality and a dozen other themes brought down the house.

The raga-like outlines and hypnotic minimalism of several of East-West's selections provided respite, although the quartet also had its own tension-building devices. Especially noteworthy was alto saxophonist Carl Grubbs' ability to insinuate the voice-like quality of his sometimes multiphonic sound into the resonating note clusters of Sanjay Mishra's sitar. Tabla player Broto Roy kept the pot boiling throughout, and pianist John Kordalewski's single-note attack, chordal comping and considered use of space were effective counterweights.

There was close and careful listening between trumpeter Young and altoist Roger Woods. No wonder, for the former was hearing one of the city's most impressive younger players and the latter was sitting at the feet, so to speak, of the area's premier be-bop expressionist. They made an excellent team as the older musician delivered reflective statements of moving lyricism and the saxophonist blew hot on one daring solo after another. "Autumn in New York" had the two taking turns at rhapsodic balladry, and Jackie McLean's "Little Melonae" was an occasion for the leader, Woods and drummer Maurice Lyles to toss back and forth every lick in the be-bop book. Pianist Aaron Graves' stately contributions and the presence again of bassist King filled out the group.

Bringing up the rear but representing the artistic vanguard was The Trio's astonishing partnership of alto sax, bass and drums. Lyons did the impossible in avoiding repetition of a single phrase as he delivered extended statements of masterly originality in a personal instrumental voice that went from shellac-smooth to clipped notes to soaring flights into upper register. He and bassist Burnett, a fluent and inventive player who can pull unlikely sounds from his instrument, were often in a sort of thematic unison, and Abadey's dynamics incorporated everything from rim tickling and barely audible sounds that simulated a finger scratching a canvas tent to groundswell from the snare that built to seismic proportions.