Grace Potter climbed out from behind her organ, grabbed one of the bouquets of carnations that decorated the Tabernacle stage and, eyes closed, spun her way to the stage’s front edge as her band, The Nocturnals, rocked the 60-minute set to its conclusion. Suddenly, as the band weaved through “Sweet Hands,” the scarlet flowers flew triumphantly into the air above the crowd with the same beauty and trajectory that Potter, the 26-year-old powerhouse from Vermont, seems to currently be mirroring across the American music scene.

Currently touring cross-country on a bill with Brett Dennen, Potter and her band gave a forceful performance showcasing the diverse abilities of the group, including Potter’s dominant stage presence, her searing vocals and The Nocturnals ability to effectively back their lead singer’s constant transitions from country, rock, funk, jam and gospel styles. This, while standing on their own as a powerful force fully capable of shaking the 3-story former Baptist church down to its knees with or without Potter’s help.

An early and swampy, deep-fried “Joey” unleashed Scott Tournet’s slide guitar and allowed the crowd to wake from their sedated slumber. “Oasis” came and went from their upcoming album before Potter’s “Apologies,” a ballad of regret and love lost, brought the lights down, while seducing the now-enraptured crowd. This song, perhaps more than any other in the Nocturnals catalog, best displays Potter’s talent as a singer and songwriter.

However, The Nocturnals are a road-hungry, full-force, four-alarm, head-bobbing rock band, as evidenced by the remainder of the set. “If I Was From Paris,” “Ah Mary” and “Mastermind” followed and are perhaps better representations of what this band is truly about; rock n’ roll in its blues-heavy, red-blooded American splendor, with songs about sex, deception, drinking and love, delivered with a striking authenticity and Potter’s honest, sweat-drenched, soulful vocals. “Nothing But The Water” was well-placed at the end of the set, its gospel strains echoing off the Tabernacle’s stained glass windows, before “Sweet Hands” closed the show to make way for the also-surging Dennen. This is legitimate, bona-fide truth music. Its strength is that of its rawness and simplicity, wrapped in Potter’s energy and might, of which she possesses plenty.