The Debonairs

From the U.K. film That'll Be the Day (1973). This late-1950s blue-suited rock and roll quintet (piano, drums, guitar, bass, vocals) play a dingy, discouraging dance hall attended by protagonist Jim MacLaine (David Essex). He's watching the band while he's supposed to be attending night school, the bastard. The band's not credited in the credits either, the bastards.

See also The Stray Cats, Stormy Tempest.