Clubs--Chicago is the hallowed ground where house music was hatched in the 1980s, so it's no surprise to find several dance clubs pounding away with a mostly under-30 crowd. A skeptical Midwestern sensibility has always reigned here, so the attitude and fashion required for a big dance club has limited appeal. But there are plenty of other clubs and bars with square footage given over to dancing. Some spots specialize in one brand of music, while others that offer an ever-changing mix of rhythms and beats that follow the latest DJ-driven trend. Given the fickle nature of club goers, some places listed below might have disappeared by the time you read this. But what's impressive about Chicago's club scene is the number of long-time survivors -- clubs that have lasted more than a year or two and continue to draw loyal crowds.