Sometimes artists like to frame their performances -- to dictate the terms on which the audience encounters their work. Last night (April 5) at the Mercury Lounge in New York City, the singer/guitarist Parker Millsap did just that as he declared the event “a rock and roll show.”

Rock and roll -- it’s a big, vague expression, but Millsap has a very specific idea in mind. He’s reaching back to the early days of the form, when the genre was a melting pot pulling freely from all types of guitar-based music, not yet a lumbering institution dominated by staid ideas.

Millsap’s a young man with an old soul, fluent in most forms of pre-synthesizer music – country and blues, folk and soul, honky tonk and rockabilly. When he was 19, he released his first album, Palisade; last year, at age 21, he released his self-titled follow-up. Though fiddles, brass and rhythm are all present, they are really just window dressing. Again and again, Parker Millsap returns to the ancient standbys: guitar and voice.

The album’s themes sometimes sound out-of-time as well -- images of sin and redemption aren’t as common in pop as they once were. Millsap doesn’t only draw on religious rhetoric: “Quite Contrary” sounds like it was strung together from old nursery rhymes, while characters in “At the Bar” get their names from The Wizard Of Oz. Occasionally, this can feel trite -- “Disappear,” for example, verges on cliché -- but more often, it helps this singer stand out. Sure, “Truck Stop Gospel” is a truck song, but it’s a long way from songs exploring the same themes on country radio.

At the Mercury Lounge, Millsap was joined by Michael Rose on standup bass, Paddy Ryan on drums and Daniel Foulks on fiddle. The fiddle and percussion mainly served to add color, filling out the skeletons defined by Millsap’s guitar. Ryan and Foulks also added comic relief, particularly Foulks, who delivered his parts with an theatrical deer-in-the-headlights expression.

The band varied their textures throughout the evening. During several songs, the drummer worked with brushes and mallets – which you might not expect at a “rock” show – to create jazzy shuffles or soft cascading fills. During “Disappear,” Rose played a walking bassline worthy of cocktail hour. Palisade’s title track ended with an instrumental breakdown that seemed to split the difference between tango and reggae.

But Millsap is an artist who defines his terms – he works best when he has a clear mission and a solid foundation. These moments in the show most often occurred during the raucous, romping portions of the set. The singer threw his whole body into the guitar, driving songs forward with twangy, bruising eruptions of rhythm. The stand-up bass was also notable on these up-tempo tracks, taking on a fierce, heavy quality, all pound and no-nonsense.

Once these sturdy frameworks were in place, Millsap slathered his impressive voice on top of the tunes. During the show, he displayed a convincing yodel, a grainy mid-range, a high Appalachian quaver and the clean, slightly-pinched sound you might encounter in innocent, late ‘50s pop. “Hades’ Plea” found Millsap howling at one moment and emitting bursts of wordless heavy breathing the next. It was a strange, brash combination – kind of like the original rock and roll.