More empty chairs than guests were visible at the National Press Club last night as the best of Washington's jazz musicians -- at least 50 strong -- donated their music to help pay the way of Cardozo High School's marching band to the Rose Bowl parade.

The small gathering did not deter the musicians: They didn't even stop jamming on schedule at 9 p.m., so caught up were they in their music.

Sax player Rick Henderson and bass player Van Perry put the night together to benefit the Cardozo band, and a slightly nervous Henderson told the quickly thrown together group and slender audience, "We're sort of going to play around with tunes; everyone take their choice."

Whenever a number seemed to slow, there was always somebody to throw in a note to keep things going. The players showed up carrying their drums and bass guitars and had a grand time of it.

"We will have about 175 in the marching group and maybe 25 or 30 chaperons," said Robert Gill, music director for the Cardozo band, as "How High the Moon" came alive in the Press Club auditorium.

Pat McCrimmon, as assistant principal at Cardozo, said, "We really are mainly concerned about their grades -- possibly if they don't get that 'C' they don't go . . . I think the students are pumped up for this . . . Even the students who are not making the trip are supporting this."

The people from the jazz clubs came to be seen and perform: Bill Harris, from Pig Foot, did his blues monologue; "Big Nick" Nicholson, with a gravelly Louis Armstrong voice, did the "Saints."

Perry wasn't sure how much money had been raised. "What difference does it make? Maybe we got one kid out and back and a new uniform. No kid should go on a long trip like that unless he is well-dressed."

It was 10 p.m. and they were still going strong.