''Mule Variations'' is an album by Tom Waits, released 1999 on the ANTI- label. It was Waits's first studio album since 1992's ''Bone Machine'' (the later ''The Black Rider'' was a collection of songs originally written for a play). It won a Grammy Award for Best Contemporary Folk Album and was nominated for Best Male Rock Performance for the track "Hold On". It also sold more than 500,000 copies world wide.
The album was backed by an extensive tour of Europe and North America during the summer and autumn of 1999, which was Waits's first proper tour since 1987. Other promotional stops included a solo performance on VH1 Storytellers.
In 2003, the album was ranked number 416 on ''Rolling Stone'' magazine's list of The 500 Greatest Albums of All Time.
The song "What's He Building?" featured in the film "Enron: The Smartest Guys in the Room" (2005). - Wikipedia