A refrain (from Vulgar Latin refringere, "to repeat", and later from Old French refraindre) is the line or lines that are repeated in music or in poetry — the "chorus" of a song. Poetic fixed forms that feature refrains include the villanelle, the virelay, and the sestina.
In popular music, the refrain or chorus may contrast with the verse melodically, rhythmically, and harmonically; it may assume a higher level of dynamics and activity, often with added instrumentation. Chorus form, or strophic form, is a sectional and/or additive way of structuring a piece of music based on the repetition of one formal section or block played repeatedly.
Usage in history
In music, a refrain has two parts: the lyrics of the song, and the melody. Sometimes refrains vary their words slightly when repeated; recognizability is given to the refrain by the fact that it is always sung to the same tune, and the rhymes, if present, are preserved despite the variations of the words. Such a refrain is featured in "The Star-Spangled Banner", which contains a refrain which is introduced by a different phrase in each verse, but which always ends:
O'er the land of the free, and the home of the brave.
A similar refrain is found in the "Battle Hymn of the Republic", which affirms in successive verses that "Our God", or "His Truth", is "marching on."
Refrains usually, but not always, come at the end of the verse. Some songs, especially ballads, incorporate refrains (or burdens) into each verse. For example, one version of the traditional ballad "The Cruel Sister" includes a refrain mid-verse:
There lived a lady by the North Sea shore, Lay the bent to the bonny broom Two daughters were the babes she bore. Fa la la la la la la la la.
As one grew bright as is the sun, Lay the bent to the bonny broom So coal black grew the other one. Fa la la la la la la la.
. . .
(Note: the refrain of 'Lay the Bent to the Bonny Broom' is not traditionally associated with the ballad of "The Cruel Sister" (Child #10). This was the work of 'pop-folk' group Pentangle on their 1970 LP Cruel Sister which has subsequently been picked up by many folk singers as being traditional. Both the melody and the refrain come from the ballad known as "Riddles Wisely Expounded" (Child #1).)
Here, the refrain is syntactically independent of the narrative poem in the song, and has no obvious relationship to its subject, and indeed little inherent meaning at all. The device can also convey material which relates to the subject of the poem. Such a refrain is found in Dante Gabriel Rossetti's "Troy Town":
Heavenborn Helen, Sparta's queen, O Troy Town! Had two breasts of heavenly sheen, The sun and moon of the heart's desire: All Love's lordship lay between, A sheen on the breasts I Love. O Troy's down, Tall Troy's on fire!
. . .
Phrases of apparent nonsense in refrains (Lay the bent to the bonny broom?), and syllables such as fa la la, familiar from the Christmas carol "Deck the Halls with Boughs of Holly", have given rise to much speculation. Some believe that the traditional refrain Hob a derry down O encountered in some English folksongs is in fact an ancient Celtic phrase meaning "dance around the oak tree." These suggestions remain controversial.
In popular music
There are two distinct uses of the word "chorus". In the thirty-two bar song form that was most common in the earlier twentieth-century popular music (especially the Tin Pan Alley tradition), "chorus" referred to the entire main section of the song (which was in a thirty-two bar AABA form). Beginning in the rock music of the 1950s, another form became more common in commercial pop music, which was based in an open-ended cycle of verses instead of a fixed 32-bar form. In this form (which is more common than thirty-two bar form in later-twentieth century pop music), "choruses" with fixed lyrics are alternated with "verses" in which the lyrics are different with each repetition. In this use of the word, chorus contrasts with the verse, which usually has a sense of leading up to the chorus. "Many popular songs, particularly from early in this century, are in a verse and a chorus (refrain) form. Most popular songs from the middle of the century consist only of a chorus."