"Down Deep Inside" is the theme song from the 1977 film The Deep. The film's score was written by British composer John Barry and the lyrics to the main theme were added by disco singer Donna Summer. The track was released as a single and became a hit in some European countries, including the U.K. The film soundtrack LP also contained a slower tempo version of the song, and an extended version of the original later appeared on a CD version of Summer's 1978 Live and More album.