A rock/pop/performance art group, the Residents have kept their identity a secret even as they released numerous music videos, albums and short films over the past four decades. In his documentary, Theory of Obscurity: A Film About the Residents, director Don Hardy Jr. explores the band's history and interviews artists such as Primus bassist Les Claypool and Devo's Jerry Casale who attest to the group's significance. The documentary also includes archival film clips and footage of performances. It makes its Cleveland premiere tonight at 9:15 at the Cleveland Institute of Art Cinematheque and shows again at 5:35 p.m. on Sunday. Tickets are $9. (Niesel)