YOU COULD call what Frontier Theory does "frat-rock," in a sense. The group comprises four Arlington brothers -- Michael, Tim, Kevin and Robert Kelley -- on lead vocals, guitars, bass and drums, respectively. But there's no Osmonds-Jacksons adolescent popism here. This is a full-bodied, adult (well, young adult) rock outfit. "No Waltz in the Meadow," the band's second LP on Top Records, is a clear progression from their fine debut, "Atlantic."

In Steve Murphy's spacious, unadorned production, the eight songs have a West Coast folk-rock sound, sort of like the best stuff that came out of the Summer of Luv, plus some extra energy and minus the hippy-dippiness. The band seems refreshingly free of the indie-syndrome -- the tendency of young bands to imitate R.E.M., the Athens bands and other independent-label successes.

Instead, the Frontier Theory performers are beginning to sound distinctively like themselves, and that sound is crystallized in the first tune, "Don't Walk Away," which opens with crisp rhythm guitar, Michael's strong, unmannered singing (which owes something to Phil Ochs), harmonies that are brotherly close without being cloying, and a tangy electric solo by Tim. Pick of the litter seems to be the frankly gorgeous "The One That Got Away," with its melancholy melody and spare acoustic-based arrangement.

FRONTIER THEORY --

"No Waltz in the Meadow" (TOP TR-007). Appearing Sunday at the Bayou.