The duets of the title aren't just musical ones -- they're the unlikely pairs who are making their wacky, road-movie way to a karaoke championship in Omaha, Nebraska. There's Todd (Paul Giamatti: Cradle Will Rock, The Negotiator), a salesman who's done a Lester Burnham and opted out of the middle-class suburban lifestyle, and Reggie (Andre Braugher: City of Angels; his is the only singing voice not his own), the mysterious, philosophical hitchhiker Todd picks up in the middle of the desert. There's Ricky Dean (Huey Lewis), a professional karaoke hustler, and the daughter he has only just met, Las Vegas casino gal Liv (Gwyneth Paltrow: The Talented Mr. Ripley, Shakespeare in Love). There's Suzi (Maria Bello: Coyote Ugly, Payback), who makes a living off karaoke and blow jobs, and the cab driver, Billy (Scott Speedman), she scams into driving her to Omaha.

Oh, and they've all got angst. Liv's mom just died, leaving her bereft, leaving her to deal with her long-lost and reluctant dad on her own; Ricky's the tough-as-nails loner who can't cope with instant family. Billy found his girlfriend in a compromising position with his business partner; Suzi's the tough-as-nails loner who takes advantage of people's weaknesses as suits her needs. Todd's wife and kids ignore him; Reggie's the tough-as-nails loner who will show him the way home. Lives are falling apart, and karaoke will put 'em back together?

Um, no. Cincinnati, New Mexico, Tulsa, Las Vegas, Utah, Florida... Duets is all over the place, and I'm not just talking about locale. With too many characters vying for screen time, Duets -- written by John Byrum and directed by Bruce Paltrow (Gwyneth's dad) -- has to leap around just to keep up, and the result is a series of disjointed stories peopled with characters we barely get a chance to know whose major turning points occur offscreen. Giamatti's rendition of Todd's spectacular nervous breakdown is the most interesting performance to watch, and not only because he has the most room to develop it. But other characters are shamefully underdrawn -- Liv's desperation for a father, a family, is mostly left to little-girlish mannerisms that are extremely annoying on a grown woman; Billy's penchant for letting people walk all over him is explained away by his former desire to be a priest, as if being a doormat is somehow the equivalent of being "good" and "peace-loving." Liv lectures Ricky at one point on how he can't handle "something real" -- i.e., a relationship with her. But there's not much going on between any of these people, not that we're made privy to, anyway. The only time these characters and this movie come alive is on the karaoke stage, but for a movie about karaoke, there's not as much singing here as you'd expect... or as the movie could have used, if only to make it more endurable.

The character quirks that go nowhere and the road-movie shenanigans that never quite get wrapped up -- like the inevitable convenience store holdup -- leave Duets feeling like Coen Brothers Light or fat-free David Lynch. Watered-down weird, this is as unsatisfying as movies get, with too much potential squandered.