Potter and Nocturnals brandish fiery rock 'n'roots

Grace Potter (pictured in September) and her band cranked out tunes in a variety of styles Saturday night. (Alberto e. rodriguez/getty images/file)

It would be simple enough to tag Grace Potter and the Nocturnals as a roots-rock act, with Potter's organ fueling a tight and soulful band that creates a perfect space for her bluesy voice. And it wouldn't be far off. But as the group closed out a three-night residency at the Paradise on Saturday, they cut a wide swath, and not just within their presumptive genre.

It started right away, with the opening cover of the Who's lovely but not overly rootsy "Getting in Tune." Elsewhere, guitarist Scott Tournet's echoing, tremolo-picked intro to "Mastermind" recalled the Yeah Yeah Yeahs over Potter's atmospheric keys, and he unabashedly spat out an '80s pop-metal solo later in the song.

Some songs took their cue from that moment. Potter's electric guitar of choice was a Flying V knockoff, and her voice galvanized into a hard-rock howl without her usual blues undercurrent on the powerfully lurching "Sinking Man" and the slashing "If I Was From Paris." It was as though Potter was casually moving into an area of rock 'n' roll that nobody was remembering to guard at the moment and claiming it for her own.

But the band wasn't abandoning rootsy pleasures, only adding to them. The Nocturnals played with a rustic soul fervor, touching on the Band and late-period Byrds as the ghost of "Drift Away" and Gram Parsons's "cosmic American music" floated through the songs. Potter sang in a rich and throaty rasp, without ache or longing, that let her offer up the dying woman's boast in "Big White Gate" that "all the folks up in heaven might like to hear me sing" without watering it down with regret.

Whatever they played, Potter and the Nocturnals were sharp, whether offering a slow, steady-moving country tune about finding relief in a bottle (but not the kind you'd expect) with the wisdom and gravitas that could only be delivered by someone who knows or playing a full-band drum solo as the climax to the gospel-fire "Nothing But the Water." But when they alternated Tournet's Neil/Angus Young hybrid solos with Potter banging her head as she pounded on her keys during the set-closing "Over Again," it was hard not to imagine them bringing rock back to roots-rock.

Tim Gearan opened with a set of comfortable roots-soul with a deep-pocket groove, though he talked too much, and too quietly, between songs, quashing some of his formidable momentum.