refrain
A recurring section of a song, usually containing the title or main message.
In Depth
A refrain is a line or section that repeats at regular intervals throughout a song, usually containing the song's title or central idea. In folk music, the refrain is often a communal singalong section — the verses tell the story while everyone joins in on the refrain.
The refrain differs from a chorus in that it is typically shorter — sometimes just a single repeated line at the end of each verse. In songs like Bob Dylan's Blowin' in the Wind, the repeated answer is blowin' in the wind serves as a refrain. Some songs use both a refrain (a repeated line within the verse) and a separate chorus section.
The oldest known song with a refrain is Sumer Is Icumen In from around 1260 — its repetitive sing cuccu structure is recognisably similar to modern pop refrains.