When the Levee Breaks" is a blues song written and first recorded by husband and wife Kansas Joe McCoy and Memphis Minnie in 1929. The song is in reaction to the upheaval caused by the Great Mississippi Flood of 1927.
It was famously re-worked by English rock group Led Zeppelin as the last song on their fourth album, released in 1971. The lyrics in Led Zeppelin's version were partially based on the original recording. Many other artists have also recorded versions of the song or played it live.
While the Led Zeppelin version is still under copyright by the band, the original song by Kansas Joe McCoy and Memphis Minnie is currently in the public domain.