It's been done before. For as long as rock 'n' roll has existed, there have been free-thinking iconoclasts willing to tinker with the makeup of the conventional rock band. Ben Folds Five raised eyebrows by eschewing guitars. The White Stripes honed their sonic attack without a lick of bass. And Matchbox 20 rose to fame without a shred of masculinity or discernible talent.

The dynamic duo of organist Kori Gardner and drummer Jason Hammel. For their fourth album, the pleasantly infectious Bring It Back, they've sprinkled a guitar flourish here and a thunderous bass line there, but their trademark sound remains intact. It is richly textured pop with a jagged edge, driven by luscious melodies and surging harmonies that evoke memories of the Beach Boys and Tigermilk-era Belle and Sebastian. It's pleasing, to be sure, and thanks to Bill Racine's heady production, it's rarely precious.

If 2003's Team Boo found the San Francisco-based duo developing a fuller, more energetic sound, Bring It Back represents an even greater leap forward. From the unabashedly pretty piano riff that opens "Think Long" to the closing strains of the epic "Running Out," it is alternately haunting and aggressively upbeat, with Gardner and Hammel trading powerfully off-kilter vocals against a background of droning synthesizers and crashing snares. It's a familiar formula, but there's a newfound sense of urgency here that helps to distinguish Bring It Back as the band's most rousing effort to date. And fittingly, they save the best for last: "Running Out" is an irrepressible anthem that begins as a plain piano ballad and gradually builds to an electrifying climax of swirling melodies and booming harmonies, with Gardner obsessively repeating the curious mantra, "I'm tired of singing." Let's hope she's being facetious.