Broadway shows run for decades these days, but somehow, the spoofery of Gerard Alessandrini’s Forbidden Broadway always seems to outlast them. When this bright little revue began mocking the Great White Way in 1982, Andrew Lloyd Webber’s Cats was yowling through the first of its nine lives, and Evita, Jesus Christ Superstar, Starlight Express, and The Phantom of the Opera were either running or threatening to open. Today, with Phantom the only Webber show left on Broadway’s boards, Alessandrini’s response is to have a stand-in for the composer sob (to one of his own tunes, of course) “Memory…is my power a memory?” Pretty much every show that’s played D.C. in recent years—Footloose, Annie Get Your Gun, The Scarlet Pimpernel, and about a half-dozen others—comes in for its fair share of abuse. And while it’s helpful to know a little something about the plays, you needn’t have actually seen them to get the jokes any more than you need to have seen Disney’s The Lion King to laugh when it’s reduced to a Mickey Mouse-sized puppet show. Forbidden Broadway Cleans Up Its Act kicks up its heels for two performances, at 6:30 and 9:30 p.m., Saturday, Oct. 28, at the National Museum of Natural History’s Baird Auditorium, 10th and Constitution Ave. NW. $26. (202) 357-3030. (Bob Mondello)