Thumbsucker features new tracks from Elliott Smith, who died before he could complete the film soundtrack. Smith's contributions are the original "Let's Get Lost" -- which would appear on the 2004 posthumous release From a Basement on the Hill -- as well as his versions of Cat Stevens' "Trouble" and Big Star's "Thirteen."

Director Mike Mills spent six years working on the film, the story -- based on Walter Kirn's acclaimed, darkly comic novel about Eighties suburbia -- of a thumbsucking seventeen-year-old, played by newcomer Lou Pucci. The movie also stars Tilda Swinton, Vincent D'Onofrio, Vince Vaughn and Keanu Reeves. Mills, who has directed live DVDs for Moby and Pulp, worked closely with Smith up until the singer-songwriter's untimely death from self-inflicted stab wounds in October 2003.

"I saw him five days before, and he'd just finished the cover of 'Trouble' for us," Mills says. "It's one of the last things he must've done. It's just sad . . . He's a huge hero of mine."

After Smith's passing, symphonic choral rockers the Polyphonic Spree, who performed at the film's Los Angeles premiere last week, stepped in to complete the soundtrack. "I think we were all sensitive to honoring Elliott's memory," says frontman Tim DeLaughter. "All we had were the three songs, and obviously it wasn't enough music. I think Elliott's single vocal and the choir really complement each other. It's very emotionally charged."

The Thumbsucker soundtrack will be in stores Tuesday, while the film opens in select New York and Los Angeles theaters on Friday.