Grace Potter on VH1 Divas Photo by Associated Press Grace Potter turned heads Sunday night at a packed Varsity Theater in Minneapolis – with her powerhouse voice, not just her pinup good looks.The fast-rising VH1 diva from Vermont uncorked her big voice. She also sang softly with more nuance and distinctive Southern soul. But there wasn't much originality to her eclectic repertoire.Nearly every number Grace Potter & the Nocturnals performed during their 100-minute set evoked someone else – Tina Turner, Heart, Amy Winehouse, the Black Crowes and Aerosmith with a female vocalist.The quintet did six songs from its self-titled album that was released last summer. In concert, "Goodbye Kiss" sounded more reggae than the new-wave-ish recorded version. "Medicine" went down like snakey classic-rock. "Oasis" featured an extended instrumental ending, reminding Varsity-goers that GPN built its reputation on the jam-band circuit. "Hot Summer Night" rocked so hard (with echoes of Tina's "Nutbush City Limits") that the crowd responded with long cheers and loud whistles.Tunes from the band's previous two studio albums showed GPN's range. "Ragged Company" was an acoustic country-tinged ballad filled with heartfelt emotion. The a cappella "Nothing But the Water" showcased the subtleties of Potter's soulful gospel voice. The ensuing "2:22" was a showy, long-winded blues-rock workout that put a spotlight on both Potter's bravura voice and the band's instrumental prowess.There's no question that Potter, 27, can really sing. Whether she can find a spot on commercial radio remains to be seen. But Grace Potter & the Nocturnals are best experienced live anyway. They would be a perfect fit for either the Minnesota Zoo or the State Fair's Bandshell. Let's hope we see them outdoors this summer.Sunday's set list:Ah Mary/ Only Love/ Sweet Hands/ Goodbye Kiss/ Big White Gate/ Oasis/ Ragged Company/ Treat Me Right/ Mastermind/ Hot Summer Night/ Nothing But the Water / 2:22/ Paris (Ooh La La) ENCORE Crazy on You (Heart)/ Medicine