He's been all over the radio dial lately, fitting because that's the format his early '60s-era sound used to break through. He's also spilling a rare and succinct batch of retro rock 'n' roll that's not just turning heads, but affixing them to his every move. But that's not why I visited the Bunk Bar Saturday night.

My interest resided in that howling, ever-eccentric, Little Richard-like voice of his. How on Earth could the body of a slight caucasian guy out of Oklahoma named JD McPherson house such elaborate vocal plumbing? It would seem like squeezing a church organ into backpack instead of a cathedral.

Upon playing McPherson's springy single "Northside Gal" to my father, a Baby Boomer, he replied, "sounds vintage, but surely there's a digital side." Perhaps, I thought, knowing full-well that his stunning debut record Signs & Signifiers was recorded with antiquated equipment and completely analog at the Hi-Style studio in Chicago. But I had not yet seen him live.

Turns out there were no digital tricks Saturday at Bunk Bar. Just a five-piece act (guitarist, drummer, stand-up bassist, saxophonist, organ player) stuck on an idea that rock 'n' roll was better in its infancy. The crowd shared JD McPherson's philosophy, a slightly older scene plucked straight from the set of Happy Days or the priceless prom scene in Back To The Future.

Bassist and producer Jimmy Sutton made his presence felt immediately, plucking violently at his upright bass. He was just as much a percussionist, slapping and plucking in time. To call them walking bass lines would be a short sell. Sutton's work was a dead sprint—save the song the record is named after, the only exhale of the evening—providing pace and a jazzy, film noir quality. Big, reverberating organ notes accentuated the mid-century urban feel.

McPherson played many types and always with gusto. In the cover on Tiny Kennedy's "Country Boy," he was preacher, spilling himself from the pulpit. In the bouncy and looping "Fire Bug," a song Buddy Holly could have written, McPherson was a pre-rock pop star, belting lyrics with a frazzled, fetching energy. In "Scratching Circles," he was Bo Diddley, projecting from his soul in frantic, fluttering vocal bursts. And in the brass-backed "Your Love (All That I'm Missing)," he went almost Motown, singing with a melodic low warble.

Just as impressive was the fact that his band followed suit, step-for-step. Every instrument added a crucial cool element that solidified the whole band's persona, without getting in the way of McPherson's howling R&B. There was texture, richness, and an infectious loyalty to a genre that is proving timeless. In a world of metal bats, these guys are a genuine Louisville Slugger.

The band took on two covers in "Farmer John" by the Premiers and "Alligator Blues" (by Boo Boo Davis?). They could have easily thumbed through a Fats Domino or Chuck Berry catalogue but instead went somewhat more obscure, to their credit. They were summoning the spirits of popular '60s musicians with every note they played anyhow.

I took one more long look and shook my head. Yes, somehow, that golden-tinged voice of old belonged to McPherson. In fact, he and his band managed to bring an entire era with them, with ease, professionalism, and just enough swagger.

Sadly, Jd McPherson won't play Bunk Bar again. Bigger venues, I anticipate, are in store.