Among trombonist Urbie Green's musically formative experiences were his associations with Gene Krupa in the late '40s and Woody Herman in the early '50s. He has spent a lot of time as a studio musician since, but frequently emerges for such club dates as his latest at Blues Alley.

It is no mystery why the studios grabbed him early. He has the control, full sound, speed and phrasing ability that is required in such work. Urbie Green demonstrated his virtuosity last night in a first set that began with "The Song Is You" and closed with "Tangerine." Throughout the set he proved an imaginative improvisor of considerable emotive range. His rendition of "Blue Monk" paid homage to his bop influences and was well-received by his attentive audience.

With Green is one of the lesser-known but truly fine jazz pianists, Dave McKenna. His solo feature, a medley of "Chinatown," "China Boy" and "Limehouse Blues" partook of stride, swing, and blues replete with Tatumesque runs and rapid changes of tempo and was both a tour de force and a compressed history of jazz piano.

Washington's own Steve Novosel, on the bass, and drummer Bernard Sweetney contributed tasteful support to Green and McKenna. The quartet remains at Blues Alley through Sunday.