Having been together for less than two full years, Nashville’s Ordinary Madmen have only one three-song EP to show for their efforts, but that sole release is a helluva thing. “The Russell Street Sessions” sounds like an undiscovered gem from some arcane-but-hella-cool ’70s rock outfit, a record redolent of black lights and psychedelic velvet posters and wafting hints of cannabis and red-eyed rock gods in bell bottoms and shaggy ‘dos.

Frontman Tyler Webb comes on a bit like late Lynyrd Skynyrd vocalist Ronnie Van Zant, only with a white-soul edge in lieu of a Southern drawl. Singing over the airtight rhythm section of  Phil Simpson and Kody Muhic, he’s ably complemented by guitarist Kyle McAllister, chief architect of the band’s throwback heavy-rock vibe via a rhythmic approach that mixes burly riffage with droning psychedelia. When it all comes together as it does on the powerful “Russell Street” epic “Love for a While,” the result recalls the best of slow-burn ’70s rock anthems — think Frampton’s “Do You Feel Like We Do” or Nugent’s “Stranglehold” or Zeppelin’s “No Quarter.”

The band gestated in 2015 when Webb, recently relocated to Nashville from Indiana, met Simpson, Muhic, and McAllister through mutual friends, the four of them pulling together a jam session/party at the house that Simpson and Muhic shared. Simpson says their project started slow, but it took off quick, and soon the foursome graduated from playing cover songs to creating their own original material.

“We’ve all been influenced by Led Zeppelin, psychedelia, and heavy blues rock,” Simpson says. “We’ve all been playing in that style for years. It’s all rooted in the blues, so I guess you could say that at the end of the day, our biggest influences are Muddy Waters and Robert Johnson.”

Simpson says the Madmen have been helped along by a burgeoning underground heavy rock scene in Nashville, a scene populated by like-minded retro rock and psychedelic artists, making for more and better opportunities to play out live.

“When Kody and I first got here years ago, it was more underground than it is now,” says Simpson, who has known — and played music with — Muhic since childhood. “But now it’s all over town, and I don’t just mean classic rock cover bands. There’s a real scene here for heavy psychedelic and garage rock.

“A lot of the bands are super raw, with some punk influence. We’ve found a place in the scene without going too far into that territory. Tyler’s voice gives us a little more finesse and soul, instead of just, ‘We’re loud and we’re going to blow your eardrums away.'”

By most any measure, the Madmen are just getting started — they recently embarked on their first significant tour, and they’re looking to release their first full-length album in spring. “We’re still trying figure out how to write with each other,” Muhric says. “I think we’re good, because we don’t have a lot of big egos in this band. We all just want to write something meaningful, and hope that somebody gets something out of it. That, and we wnat to drink beer and have some fun.”

Ordinary Madmen will play Preservation Pub Sunday, Jan. 7 at 10 p.m.