"You don't even know who Liz Phair is," Liz Phair sings to a younger lover on "Rock Me," one of the more palatable songs on her long-awaited, self-titled fourth album. But who can blame him? Even Phair doesn't seem to know who she is anymore. An artistic identity crisis in CD form, the disc has a little bit of confessional singer-songwriter material, a little bit of more calculated pop, and a lot of stuff so fussed-over that it sounds less like music than like demographically tested sonic sculpting. Phair never got enough credit for Whip-Smart and Whitechocolatespaceegg, solid albums that injected color into the grainy black-and-white imagery of her landmark debut Exile In Guyville. On Liz Phair, she seems to cop the attitude that since everyone always accuses her of selling out, she might as well go all the way with it. That includes roping in The Matrix, the production team behind Avril Lavigne's recent hits, which Phair has made no bones about attempting to emulate. But since Lavigne wants to sound like early Alanis Morissette, and Morissette started out trying to do a slicked-up impression of Liz Phair, isn't that a bit like Bruce Springsteen hiring away Jack Johnson's collaborators? That doesn't stop The Matrix from going all-out to push the album's first single, "Why Can't I?," over the top, but it's an embarrassingly awkward marriage of dumbed-down Phair songwriting and every tired production trick of the last year. (Some voices just weren't made for distorted echo effects.) The album mostly fails to improve on that low standard. It's hard to sound condescending singing to a child, but Phair pulls it off with "Little Digger." The lover-as-underwear metaphor of "Favorite" wouldn't work even with a better tune, and the semen-as-skin-conditioner ode "H.W.C." seems thrown in out of some vestigial desire to shock. Worst of all, the album closes with three decent songs, reminders of Phair's talent that are muted by what's come before. Maybe there wasn't time for that Clay Aiken duet.