Not to be confused with Boston or Kansas, Chicago forged a driving, horn-filled, white jazz-rock-soul sound before staggering into their later romantic ballad era, which eventually led to grizzled-geezer casino tours. Their many platinum-selling hits were catchy enough to stay in your head after just a glance at their title ("25 or 6 to 4," "Saturday in the Park," "You're the Inspiration").