The Doors: Back Door Man (1967)

A "back door man" is someone having an affair with a married woman. When the husband leaves, the other guy comes in the back door. The term dates to the 1920s. In the 60s, people began using to term to refer to "anal intercourse." Howlin' Wolf recorded the original in 1960. The Doors covered it seven years later and became a song that defined Jim Morrison, but also the sexual revolution.

Howlin' Wolf:

http://www.youtube.com/watch?v=RBd4PPZV6QI

The Doors (studio):

http://www.youtube.com/watch?v=jChqf7syif0

The Doors (live):

http://www.youtube.com/watch?v=4-EIi7ToTkA