Old 97's, featuring Rhett Miller, at TLA

Pop music has no shortage of seductive crooners and sexual braggarts, but these days romantic rascals are in short supply. With his floppy hair and cloudless blue eyes, Rhett Miller of Old 97's looks perpetually boyish, a vulnerable idealist laid open to the cruelties of the world, especially a few hard-hearted members of the opposite sex. It took only one look at the crowd in the sold-out TLA on Saturday to know that more than a few members would have been happy to soothe his oft-broken heart.

There's a healthy dose of vinegar mixed in with Miller's more syrupy sentiments, echoed in the band's mixture of heart-on-its-sleeve country and roadhouse swagger. At the TLA, Miller followed "Question," a plangent marriage-proposal ballad that has scored innumerable first dances, with the spiky "Designs on You," in which he's the other man trying for one last score before his sweetheart ties the knot.

Over two sweaty and energetic hours, the set list worked to balance the scales, although within songs the proportions were sometimes out of whack. The youthful braggadocio of older songs such as "Barrier Reef," in which Miller proclaims himself a "serial lady-killer," went down smoothly enough, but the sluggish "Love Is What You Are," from the band's new album, The Grand Theatre, Volume One, stuck in the throat like a misshapen bonbon.

Hayes Carll, who opened the show, doesn't cut his acid with sugar, but he pours it slowly, drinking as much as he serves up.

In "Another Like You," a boy-fights-girl duet from next year's KMAG YOYO, he is a left-winger giving worse than he got from a Fox News firebrand, their romantic chemistry fueled by the political shouting match.

On the album's title track, taken from a military acronym that ends, "You're on your own," Carll spins the tale of a teenager out of his depth in Afghanistan, rewriting Bob Dylan's "Subterranean Homesick Blues" for the new millennium. The song is sardonic but not glib, neatly encapsulating the gallows humor of a combat zone and sufficiently scathing to win jaded hearts on both sides of the political fence.

Carll is more of a droopy dog than a lovesick hound; the tour-bus lament of "Hard Out Here" pushes past pity into a self-mocking whine. But he knows how to get the crowd on his side, even if he can't muster much enthusiasm for the cause himself.