From Zappa Wiki Jawaka
Tom Waits (Pomona, California, July 12, 1949) is an American singer and pianist. As a child would keep a pad of paper and pencil by his bed so that he could write down the lyrics he thought up in the middle of the night. He taught himself how to play the piano at a neighbor's house, and then learned the guitar. Waits got into the music business at an early age; Herb Cohen signed him to Asylum records in '71 ('discovered at a "Hoot Night" at The Troubadour). Tom Waits opened for The Mothers on a number of occasions, and sat in with the band at least twice: 8/11 and 11/9 of 1974.
Waits' early music (1973-1983) can be described as late night piano music in a bar and is actually quite accesible. His later work, from 1983 on, was more underground style music combining rock and folk music. He has a very recognizable growling voice, which is similar to that of Captain Beefheart.
Tom Waits' Restaurant is mentioned in the lyrics of some Stink-Foot versions.
Waits named Trout Mask Replica and The Yellow Shark as two of his favourite albums. (http://www.guardian.co.uk/music/2005/mar/20/popandrock1)