PREVIEW Imagine the unsavory digs of the Mos Eisley Cantina of Tatooine stormed by a horde of previously barred droids and miscreants and forced to hold a variety show to stave off certain destruction — it's a scene reminiscent of those generated by San Francisco's OmniCircus, which has been simultaneously thrilling and troubling audiences for two decades. Founded by local surrealist artist and roboteer Frank Garvey, first as a film project, then as a live performance troupe, OmniCircus combines the high tech with the lowdown, propagating an environment where down-and-out robot performers and their human counterparts can come together under one roof, creating a spectacle part Transmetropolitan, part Captured! By Robots, and part The Black Rider. No mere vehicle for cream pies and contortionists, this darkly subversive one-ring circus has all the hallmarks of an ecstatically apocalyptic experience: music, mayhem, and mechanical mendicants. The Thousand Faces Ball marks the latest incarnation of the project, introducing the Moth nor Rust band starring OmniDiva Joan Loon, and retaining the talents of longtime DeusMachina collaborators, including Daniel Berkman and Geoffrey Pond, as well as an army of robotic riffraff: junkies, beggars, street preachers, and whores. Billed as the world's first robotic theatre ensemble, OmniCircus is nevertheless no ephemeral vision of the future, but a thorough examination of the present through an unsentimental, yet curiously life-affirming lens.

THE THOUSAND FACES BALL Sat/8, 8 p.m., $10 donation. OmniCircus, 550 Natoma, SF.

(415) 701-0686, www.omnicircus.com