On Under the Blacklight, Rilo Kiley's major label debut and first release since 2003, the band has gotten decidedly more adventurous.

Blake Sennett's guitar work is as alt-country as ever, but this time around most of Rilo's rhythm section is straight R&B. The end result is something that sounds not unlike a Loretta Lynn-fronted Son Volt covering 1980s Michael Jackson, all anachronisms notwithstanding.

That may actually be the weirdest comparison I've ever made, but don't let the esotericness mislead you: This is still an accessible album.

The band's roots will always be deceivingly folksy, and such roots are still evident even amidst the major-label glitz. But on Under the Blacklight, major strides are evident and the band explores several different genres, disco and funk included. It's hard to figure out if this album is a progressive step toward a new sound or just an out-of-character fluke.

At the same time, it regularly balances sugary pop music with dark -- and often overtly sexual -- subject matter, and it becomes difficult to discern the mood the band is trying to convey.

Still, some of Under the Blacklight is a little more straightforward. In the interest of full disclosure, I should admit that I have a tremendous crush on Jenny Lewis, but I'll also argue that the most attractive thing about her is her fantastic voice. And that's saying something. She's got a phenomenal vocal range, the versatility to let her words drip with just the right amounts of sex or soul as the situation dictates, and an uncanny ability to deliver lines like "Ooh, it feels good to be free" and "You got to give a little love...to get a little love" with just enough emotion and genuine conviction to make them sound not nearly as trite as they do when written out like this.

Lewis' voice makes up for more than her lackluster lyricism; her charmingly seductive vocals often carry the band when its other members can't pull their weight. This is no more evident than on "Dreamworld" -- a song that's lead vocals are provided by Sennett instead of Lewis -- when she is conspicuous in her absence and the momentum from the preceding title track lags a bit. Even on a song like "Smoke Detector," which features what might be the lamest conceit on the album, her sultry-yet-saccharine hooks don't dissolve in the otherwise watery tune.

Under the Blacklight certainly isn't Rilo's magnum opus -- and in one or two respects, it might even be the band's nadir -- but Lewis' vocals are at their very best, and that alone makes it a solid listen.

Grade: B-