ART: Spoke Art presents the group exhibition, The Bridge is Over, which features the work of artists who live and work in the East Bay, showing San Francisco "the quality of work, and strength of the scene, that exists just over the Bay Bridge."

6 to 8 p.m. // Lopo Gallery (1141 Polk St) // free

MUSIC: Godfather of hip-hop and one of the three main originators of break-beat deejaying, Afrika Bambaataa, is in SF for a one-night Zulu Nation show only -- featuring an open dance floor. Not to be missed!

10:30 p.m. // Yoshi's San Francisco (1330 Fillmore St) // $16

VIDEO: Optronica, the first in a three-part exploratory sound series, Testing...Testing, features the giddy emergence of multiple-projection video with live music, including works such as a three-wall immersive environment of "stereoscopic imagery" and homemade "Hologlyphics."

8 p.m. // ATA Gallery (992 Valencia St) // $7