Pop your head into Tampa Theatre at a certain point Thursday night and you’d have seen an audience rapt and silent, all eyes and ears focused on the performer at center stage.

Look in a while later and you might have thought you’d stumbled into a loose rehearsal-dance party, as a crowd shimmied in front of the stage and the show’s star playfully relieved a few of their purses and wallets.

Nashville never knew what to do with Shelby Lynne and Thursday’s performance showed why. She lives and performs in the moment, following her muse rather than the rules.

Her performance of “Anyone Who Had a Heart” was Lynne at her most vulnerable. Her keyboard player left out a chord during the intro, leaving Lynne’s voice alone, unprotected and stunningly affective.

But “You Don’t Have to Say You Love Me” topped even that. She sang the intro with little accompaniment, securing the crowd’s undivided attention. She finished one line with a slight smile on her face, then frowned for an instant that felt like an eternity before beginning the next one. It was the slightest gesture but conveyed so much emotion, the mark of a great performer, one who absolutely inhabits the song.

But the mood lightened once Lynne and her fantastic four-piece band swung into the groove of “Gotta Get Back,” which brought a lone dancer to the front. She was joined by a couple more brave souls, and then some more and then some more. Soon the front of the stage was filled with swaying fans as Lynne offered to take the ladies’ purses so they could dance more freely, and then relieving one gentleman of his wallet as well.

The set drew heavily from her breakthrough album, 2000’s “I Am Shelby Lynne,” and this year’s Dusty Springfield tribute, “Just a Little Lovin’.”

But she also included cuts from other albums, including “Johnny Met June,” “Jesus on a Greyhound” and “the song I wrote for that movie I hated,” as she referred to “Killin’ Kind,” from the soundtrack of “Bridget Jones’ Diary.”

So few performers take any risks at all anymore. That just made Lynne’s performance all that much more thrilling.