Thirty-two-bar form

The 32-bar form, also known as the AABA song form, American popular song form and the ballad form, is a song structure commonly found in Tin Pan Alley songs and other American popular music, especially in the first half of the 20th century.[2]

"Over the Rainbow" (Arlen/Harburg) exemplifies the 20th-century popular 32-bar song.[1]

As its alternative name AABA implies, this song form consists of four sections: an eight-bar A section; a second eight-bar A section (which may have slight changes from the first A section); an eight-bar B section, often with contrasting harmony or "feel"; and a final eight-bar A section. The core melody line is generally retained in each A section, although variations may be added, particularly for the last A section.

Examples of 32-bar AABA form songs include "Over the Rainbow", "What'll I Do", "Make You Feel My Love",[2] "Blue Skies",[citation needed]. Many show tunes that have become jazz standards are 32-bar song forms.