A refrain structure in which an initial A section is followed by a second A section of identical musical material, followed by a section of contrasting musical material, and concluded with a repetition of the initial A section. Lyrics change in each section, but there is usually a repeated lyric in the same location of each A section (e.g., lyric is repeated either the beginning or the end of the A sections). Generally this corresponds to a refrain of typically 8-bar sections. AABA refers to the structure of the Refrain, not the structure of the song.