Just for the record, the documentary "Mr. Gaga" has nothing to do with a certain superstar American singer who dropped from the roof of NRG Stadium during the recent Super Bowl. Performed by a large cast that grows increasingly intense as they thrash on a semicircle of chairs, gradually tossing their clothes as they strip from black suits to their skivvies, it's a stunningly physical rendering of a percussive chant from a well-known Passover song. Director Tomer Heymann, who appeared in Houston for a January screening of "Mr.