Along with Columbia Records label mates Blood, Sweat and Tears, Chicago spearheaded the horn sound of the early 1970s. Striking a balance between the big band and jazz elements of a pronounced horn section with the more traditional rock ‘n’ roll foundation of a four piece guitar-bass-drums-keyboard unit, Chicago would prove to be one of the most prolific bands of the decade and enjoyed remarkable career longevity. Since they emerged in 1969, with the now legendary Chicago Transit Authority double album, they maintained a near-locked position in the Billboard Top 40.