You haven't seen a movie musical until you've seen Singin' in the Rain; it's so full of huge production numbers, catchy songs, and fancy dance steps that it makes Chicago look like Lady in the Water. Ostensibly about the troubled times when Hollywood changed from silent movies to talkies, Singin' in the Rain is a chance for Gene Kelly, probably the Most Talented Human Being on Earth at the time, to show off. It's physically impossible to watch the slapstick dance number "Make 'Em Laugh" without dropping your jaw in awe. (Central Cinema, 1411 21st Ave, www.central-cinema.com. 9:30 pm, $5 adv/$7 DOS, 21+.)