For several years now, the Smithsonian's American Dance Experience series has afforded audiences a chance to look, listen and understand the glories of jazz tap dancing. "From Rhythm to Bebop--and On!," this past weekend's program devoted to the art of improvisation, was the most sophisticated, aurally challenging offering thus far; judging by the absorbed silence/wild cheering that filled Baird Auditorium, the Smithsonian's education-through-entertainment plan certainly has paid off.

The six performers who created and traded rhythms Saturday night--tap masters Steve Condos and Jimmy Slyde, pianist Barry Harris, trombonist Slide Hampton, drummer Grady Tate and bass player Keter Betts--share that ease and creativity that grow out of rock-solid technique and awesome personal style. Beginning with a standard Parker or Ellington or Gershwin tune, each would expand upon, weave in and out of, or transform a melodic or rhythmic line until it belonged to him. Brawny, good-natured Condos doubled, then quadrupled, a phrase and sent out a mellow, "tenor" tap sound. Elegant Slyde played tag with the musicians, sliding literally and figuratively about the floor and the tunes, bounding up on his toes, making wild shapes in space with his tiny frame. Harris played an ultra-smooth, achingly rich piano; Hampton's trombone wrapped the listener in a muted, romantic fog; Tate sang a detailed, sexy "My Funny Valentine" and sent some stormy riffs in the dancers' directions; Betts brought down the house by turning his bass into a flamenco guitar, complete with virtuoso bowing and dazzling arpeggio work.