The Green Mill is the most authentic jazz club in the city, hands down. People don’t come here to socialize (and if they do, they may get hushed), they come for good, solid jazz. The sultry but bare-bones jazz club, which started as a roadhouse in 1907, used to be an Al Capone hangout, and remains a living museum of 1930s Chicago. Arrive early (8pm) or late (midnight) if you hope to nab a barstool or booth. The place gets elbow-to-elbow packed during its nightly shows, which range from traditional jazz to more challenging tunes. Because the music goes until the wee hours (4am during the week, 5am on Sat), you can often catch touring musicians stopping in to jam here after finishing up their own shows across town. On Sunday nights, it hosts the famous Uptown Poetry Slam.