Billy Bob Thornton's return to music:
Around the time Sling Blade was being filmed, Thornton got back together with some old bandmates and held jam sessions, providing entertainment for the film crew. This became habit, and Thornton began doing this for several of his films.
Not long after, Thornton was urged by friends to begin writing his own music and recording. 2001 saw the release of "Private Radio," his debut album, described on his website as "dark, profoundly personal, and moving."
"The Edge of the World" is Billy Bob Thornton's sophomore album, released in 2003.
Thornton formed a band for the albums, bringing professional musicians together for the work. This includes country acoustic guitarist Brad Davis, keyboardist Teddy Andreadis (formerly of Guns 'n' Roses), psychedelic rocker Mike Shipp, guitarist Randy Mitchell, guitarist Steve Bruton (who had worked as a producer alongside Bonnie Raitt, Bob Dylan, Willie Nelson, and others), singer Mica Roberts, bassist Steve Arnold, drummer and classical percussionist Sam Bacco, and a number of guest stars, including Tommy Shaw of Styx.
In addition to these two solo albums, Thornton has lent his vocals to other musicians' work as well; he and banjo musician Earl Scruggs covered Johnny Cash's "Ring of Fire," and he recently provided a rap for Styx's "Cyclorama" album (something I would like very much to hear).
Props to allmusic.com and billybobthornton.net, from where I gleaned this information.