The Webster Young Octet almost outnumbered its audience Monday night at d.c. space in the concluding session of District Curator's five-day festival. Nevertheless, the handful of the faithful in attendance was treated to an opening set that was part workshop and part straight-ahead jam, several of the numbers running to nearly a half-hour with everyone taking his turn for an extended solo.

The trumpeter leader's warm tone, vibrant timbre and lean lines on "Tomorrow's Expectation" combined for an emotion-filled statement, and "Moon Trane" had Young's horn swallowing the mike for resonating flutters and echo effects.

The thick texture of two electric pianos (manned by John Kordalewski and Larry Scott) was laced with the brittle soprano sax of Gary Hart and the foggy tenor of Russell Carter, an effective contrast. Maurice Lyels, a drummer of whimsical humor, bassist Fred Williams and conga player Carter El were a solid rhythm team.

During the intermission, acoustic guitarist Mantuila Nyombo's eclectic repertoire, his surpassing--if unorthodox--skills of execution, and massed sound that can suddenly drop to single-string whisper or finger-drumming on the guitar box convinced that here is an underground talent whose time has come.