Spring were a Leicester-based British progressive rock band that represented the early 1970s progressive rock movement. A one-shot band, it released only one album in its career, a self-titled LP released in 1971. Spring's music is notable for the use of the mellotron with three of the its five members credited with playing that instrument on the album. Songs for a second album were recorded but not released at the time. They were later released on CD together with some demo's as "The Untitled 2".