Earnestness and irony split the triple bill at the Knitting Factory on Friday night, because Papas Fritas, the headliner, had some of both. By their sound alone, Papas Fritas's songs should be effervescent pop, with nothing more on their mind than the next infatuation. Their transparent arrangements hark back to Mersey-beat bands and the lighter songs of the Replacements; bass and guitar riffs are neatly placed, and there are plenty of nonsense-syllable hooks, from "na-na-na-na" to "bop-ba-dop."

But Papas Fritas, a trio formed in 1993 by three Tufts University students, aren't entirely old-fashioned. While some songs, like the deceptively buoyant "Smash This World," deal with romantic ups and downs, others remain more elusive. In "TV Movies," when Tony Goddess (on guitar) sang, "What's your name, how you doin'?," Shivika Asthana (on drums) responded, "TV movies, made for TV."

On Friday night, Papas Fritas deliberately disrupted the crisp outlines of their songs; Mr. Goddess used a more aggressive guitar attack than he does on the band's album, "Papas Fritas" (Minty Fresh). Unfortunately, his voice was hoarse and frayed, and the obvious effort upset the balance of Papas Fritas's songs, reducing their crafty nonchalance.

Ditchcroaker, a three-man band from Hoboken, opened the bill. The band is among alternative-rock's many Neil Young disciples, with a touch of R.E.M., playing midtempo songs with fuzzed guitar and ambiguous lyrics: "Been tossed around now our minds are changed/so far ahead of ourselves we fall behind." While the sound is familiar, Ditchcroaker uses it well; its songs gather tension and power as they unfold. All the band needs is a little more variety; not every song has to start with its basic guitar riff.