Tap dancers make me feel I'm caught in some weird dream, just barely making out what they're saying with their feet. A soloist is giving a monologue, two or more dancers are having a conversation, and a group like Brenda Bufalino's American Tap Dance Orchestra, which features dozens of performers onstage at once, is a Greek chorus. Unlike most other kinds of dance, tap is largely a matter of listening--but you wouldn't close your eyes any more than you would during a conversation; you can tell who tap dancers are not only by the way they talk and what they say but also by how they look while they're saying it. Savion Glover's light, strong, quick, ingenious steps reveal his youth and exuberance. In Sarah Petronio's tapping you can hear diffidence and self-assertion alternate. And with Jimmy Slyde you can hear the confidence of his 60-some years, the willingness to play around, to make a joke, even to stop dead in his tracks. People will wait, he seems to say, and the wait will be worth it. You can see these three plus tap greats Bufalino (sans orchestra), Lon Chaney, Ted Levy, Chuck Green, and Van Porter and newcomers Acia Gray, Leela Petronio, Karen Callaway, and Mark Mendonca, backed by four of Chicago's top jazz musicians, in the first-ever Chicago on Tap festival, sponsored by the Dance Center of Columbia College and the Old Town School of Folk Music. The week-long festival kicks off Monday with workshops and master classes and free previews and tap jams (see listing); regular performances are next Friday and Saturday, July 22 and 23, at 7:30 and next Sunday, July 24, at 3 at the Navy Pier Skyline Stage, 600 E. Grand; $18.50-$21.50. Call 902-1500 for tickets, 271-7928 or 525-7793 for information.