Until it Sleeps is the 4th song from Metallica's 1996 album Load, and is written by James Hetfield and Lars Ulrich.
The song was an instant radio hit and predominantly marked Metallica's further departure from their previous thrash metal stylings into the realm of more alternative rock and bluesy music. The song was also performed with orchestral accompaniment during S&M. It was the band's first #1 on the Mainstream Rock charts, as well as their first and only song to hit the top 10 of the Billboard Hot 100.
An early demo version of this song was entitled "Fell On Black Days", because the demo reminded the band members of the Soundgarden song of the same title .