Chicago is an American rock band formed in Chicago in 1967. The group began calling themselves the Chicago Transit Authority in 1968, then shortened the name in 1969. Self-described as a "rock and roll band with horns," their songs often also combine elements of classical music, jazz, R&B, and pop music.

William Bradford Champlin is an American singer, keyboardist, guitarist and songwriter. He formed the band Sons of Champlin in 1965, which still performs today, and was a member of the rock band Chicago from 1981 to 2009. He performed lead vocals on three of Chicago's biggest hits of the 1980s, 1984's "Hard Habit to Break" and 1988's "Look Away" and "I Don't Wanna Live Without Your Love". During live shows, he sang the lower, baritone, vocal parts originally performed by founding guitarist Terry Kath, who had died in 1978. He has won multiple Grammy Awards for songwriting.