Chicago

Before embarking on an unusually long career as purveyors of soft-rock ballads, rock's most successful horn-heavy ensemble started out both artistically progressive and politically engaged.

Known as the Big Thing when they formed in 1967, the prolific Second City septet released their eponymous debut album as the Chicago Transit Authority two years later.

In addition to a sidelong epic devoted to political liberation and Terry Kath's extended guitar freak-out, the record also yielded keyboardist Robert Lamm’s hit single “Does Anybody Really Know What Time It Is?” After shortening their moniker at the behest of the real CTA, Chicago stretched out over three subsequent multi-disc albums that paired classic-rock staples like \