Some 45 years after their first appearance on a San Francisco stage, The Residents remain a band that practically defines the term "cult," and their freak-show, cartoon-surrealist approach continues to attract a healthy fan base (as evidenced by some sold-out shows at Tokyo's Blue Note back in March).

It was only a matter of time before someone gave The Residents their own rock doc, but director Don Hardy Jr.'s "Theory of Obscurity: A Film About The Residents" faced an unusual problem: How do you dig into the history of a "band" that has remained defiantly anonymous throughout its career?

Who lurks behind the top-hatted giant-eyeball masks is a question that has long been shrouded in mystery, which has led to much speculation. (The Beatles were prime suspects, then David Byrne.) "Theory of Obscurity" does not unmask the band, but it does include interviews with current and former members of the Cryptic Corporation — their business/management arm — and it's likely that some of them have seen the inside of an eyeball mask.