They claim to be refugees from Planet A, which circles the star Cappella in the constellation Auriga . . . and who knows? If their sense of humor is any indication, it's probably true. One thing is for sure: when the Edlos take the stage, this quartet of unaccompanied singers never fail to transport entire audiences with their unique combination of outrageous gags and impeccable musicality, post-modern dynamics, and inventive vocal arrangements of everything from Gregorian chants to the songs of the Beach Boys as well as bizarre originals like those found on their new '60s album, Retropella. Behind the jokes, costumery, wigs and other assorted mayhem, Eric Morris, Ed Cohn, Larry Venza, and Craig Knudsen all have stellar reputations as classical performers -- they're veterans of the San Francisco Opera Company and Pocket Opera, among many others -- but that doesn't prevent them from having a good time, as tonight's concert how is sure to prove.