Recent fans of Copenhagen who missed Michael Frayn's 20-year-old London hit Noises Off may not recognize their man. Copenhagen is a sober historical play about quantum physicists during World War II, trying to develop (or thwart) the atom bomb. Noises Off is a wild farce about a stage company touring the British provinces in a disastrous sex romp called Nothing On. The star, Dotty Otley, keeps missing her cues and lines as a heavily accented charwoman, trying to look after a (supposedly empty) vacation house and relax with a snack of sardines. The complications in Nothing On are thin compared to the complications backstage, and in the uproarious second act we get to watch the actors as their jealousies, romances, and deceptions boil over while they try to keep Nothing On from imploding. Jane Carr is beautifully batty as Dotty; Dan Hiatt is a perfect horse's ass as Frederick Fellowes, the other (very pompous) star of the show; Ali Taylor plays a charmingly harried stage manager, Poppy Norton-Taylor; and Jamie Day is the hilariously stiff and dim Brooke Ashton, who looks great in lingerie but can't improvise to save her life when her colleagues go careening off-script. Richard Seyd directed the Bay Area premiere of Noises 15 years ago, in Marin; he's back with an equally triumphant revival.