Verse-chorus form is a musical form common in popular music and predominant in rock since the 1960s. In contrast to AABA (thirty-two-bar) form, which is focused on the verse (contrasted and prepared by the bridge), in verse-chorus form the chorus is highlighted (prepared and contrasted with the verse). Covach, John. "Form in Rock Music: A Primer", p.71, in Stein, Deborah (2005). Engaging Music: Essays in Music Analysis. New York: Oxford University Press. ISBN 0-19-517010-5.