Wash U kids take their nightlife seriously. For the first couple of years, most like to stay on or around campus and enjoy the frat parties, sophomore suite parties, and off-campus house parties. Frat Row definitely attracts a crowd every weekend, although it's not everyone's scene. There are a few bars around town that don't card too hard, as well, so it's possible to start exploring before turning 21. With a real (or quality fake) ID, a lot more of St. Louis nightlife opens up. There are tons of blues bars, like BB's Jazz, Blues, & Soups and Library Annex, and music venues that are more 21-and-over friendly than underage-friendly, like The Pageant and Broadway Oyster Bar.
For people with more eclectic or refined tastes, St. Louis has some other options besides bars and parties. The Backstage Bistro is a classy jazz club downtown, which features top performers like Ahmad Jamal and Joshua Redman. Next door is the St. Louis Symphony, one of the best in the country, which performs every Friday and Saturday night during the season. There are also a few clubs downtown for those with a taste for loud music and close quarters. Washington Avenue has a strip of interesting venues, and by keeping an eye on the flyers posted in the Loop, it's easy to find out about DJ events, the occasional rave (mostly for high school kids, though), and hip-hop parties.