There are a lot of reasons to love Frank Oz's big-screen musical adaptation of Little Shop of Horrors, the tale of Seymour Krelborn and his killer plant—the doo-wop girls' bouncy sass, Audrey's lisp—but my favorite performance is also one of the 1986 film's shortest. Bill Murray shows up for four minutes as a masochistic dental patient, a man so turned on by the sound of Steve Martin's drills and suction that he fairly writhes with pleasure upon Martin's reclining chair, ecstatically mumbling the mantra "Candy bar, oooohhhhh candybar-candybar-CANDYBAR!!!" through a mouthful of gauze to climax. It's hilarious, silly and disconcerting—much like the campy film itself. Bagdad Theater. 9 pm Thursday, Jan. 20. $3.