Here's what's going on today (Friday, August 10): Theater weekend begins with two shows: Avenue Q at Bay Street Theatre (7:30 p.m.) and What the Butler Saw at Muse Arts Warehouse (8 p.m.). Comedian Jim Gaffigan is onstage at the Johnny Mercer Theatre at 7 p.m. Catch the Train Wrecks and Tonto at the Jinx, the Royal Noise at Congress St. Social Club, and/or Doug Mains & the City Folk at the Sentient Bean.