"Why Should the Fire Die?"

Sugar Hill

Acoustic pop band? Contemporary folk trio? Newgrass upstarts? Nickel Creek has always defied labeling, and the job hasn't become any easier now that the Grammy winners have switched producers. Alison Krauss has moved on, replaced by a pair of rock vets: Eric Valentine (Good Charlotte and Queens of the Stone Age) and Tony Berg (Aimee Mann, Michael Penn and Edie Brickell).

Though flawed, "Why Should the Fire Die?" is Nickel Creek's most ambitious and sophisticated album, distinguished by atmospheric (and sometimes brooding) songs instead of tuneful accessibility. Guitarist Sean Watkins's ballad "Somebody More Like You," for instance, is pitched somewhere between unforgiving and menacing. "Jealous of the Moon," composed by Nickel Creek mandolinist Chris Thile and the Jayhawks' Gary Louris, is mournful and ironic. ("You drag your pretty head around swearing you're going to drown / With a beautiful sigh in a river of lies.") Another album highlight is fiddler Sara Watkins's "Anthony," a bittersweet ode that sounds like something right out of the Victrola era. Then there's Thile's "Doubting Thomas," surfacing near the end of the album and contributing a spiritual interlude. Vibrant contrasts play a role as well, with some tunes pointing to the group's affection for bluegrass and country rock, but the most memorable tracks are soulfully evocative and subtly arranged.

As for the miscues, they're minor. Sara Watkins's interpretation of "Tomorrow Is a Long Time," for one, is yet another addition to that ever-growing list of routine Bob Dylan covers. It's the original songs, especially the ballads, that find Nickel Creek moving forward and looking inward.

-- Mike Joyce

Appearing Sunday at the 9:30 club.

Nickel Creek's Chris Thile, left, Sara Watkins and Sean Watkins won't be pigeonholed.