It’s Saturday night on Frenchmen Street. In the Spotted Cat Music Club, the crowd is grooving to the New Orleans rhythm-and-blues-inspired sounds of singer/pianist Davis Rogan and his band.

“Yes, indeed,” Rogan says just before the show starts. “And here we go.”

They open with “Junco Partner,” a local standard recorded by the likes of Professor Longhair, James Booker and Dr. John.

“That’s our show opener,” Rogan said a few weeks later during a weekday afternoon interview. “I love the New Orleans rhythm-and-blues tradition and, obviously, the piano players and the funk and the passion. It’s real.”

Rogan took a handful of lessons from local pianists Tom McDermott, Jon Cleary and Edward Frank, but he’s mostly self-taught. Rogan didn’t start playing the instrument until he was a freshman in college.

“You can probably get a book about how to be a low-down piano player,” he said in a characteristic gush of words. “But another way to get there is to start late and not take any formal training.”

Rogan’s history includes rapping with the ’90s funk-rap band All That; deejaying at WWOZ-FM; working as an itinerant music teacher in the Orleans Parish Public Schools; and scoring “Treme,” the HBO series about New Orleans after the flood.

“Out of all of my heroes, like Allen Toussaint, out of all of my peers, like Galactic, I got the most music on the show,” he said.

In addition to scoring the series, Rogan, a longtime resident of the Treme neighborhood, inspired one of the show’s principal characters.

Actor Steve Zahn played Davis McAlary, a casual musician but passionate champion of the city’s music and culture. The real Rogan can be seen in recurring cameos in the series as the piano player in the McAlary’s band.

Rogan recently released his third and best solo album, “Ex Machina.” It’s soaked in New Orleans. He is far more serious about music than the dilettantish gadfly Zahn portrayed in “Treme.”

“I wish that Davis McAlary had spent more energy working on playing and singing,” Rogan said. “But at the end of the day, people know there was a ‘Treme’ character named Davis who was based on me. It’s done wonders for my career.”

Rogan and his band are performing Friday at Three Muses. The other local venues they play include Richard Fiske’s Martini Bar & Restaurant and Buffa’s Bar & Restaurant.

“But for some reason, I play New York and Chicago more often than I play Uptown New Orleans,” he said. “Chicago is a land with a strong theatrical tradition, so people sit and listen in a way that they’re not used to doing here. I’m proud of my piano playing, and my band sounds great, but I have another component, which is the words. There’s a payoff in listening to the words.”

His “Ex Machina” album lyrics are worth hearing. For instance, in the allegorical, voice-and-piano “Big Treezy,” Rogan offers funny observations about New Orleans’ many newcomers. In “Mr. Rogan,” he raps comically about his teaching career.

The latter songs follow comic precedents in the songs of Professor Longhair (“Bald Head,” “Hey Now Baby”), Huey “Piano” Smith (“Rocking Behind the Iron Curtain,” “Little Chickee Wah Wah”) and others.

“There’s a sly, winking playfulness in the lyrics from all of those guys,” Rogan explained. “I try my best to carry that torch.”

Another “Ex Machina” song, “Dapper Dirty Old Man,” pays tribute to the late Uncle Lionel Batiste. Rogan can’t believe he’s the only local musician, so far, to write an ode to Batiste, the Treme Brass Band bass drummer who died in 2012.

“Come on, people,” he said. “This man deserves lionizing and praise.”

Every “Ex Machina” song is an original composition, except “Will You Love Me Tomorrow.” Rogan casts the 1961 hit by the Shirelles in a New Orleans R&B mode. Travis Blotsky, tenor and baritone sax in Rogan’s band, wrote the Dave Bartholomew-inspired wall-of-sound horn arrangement.

“I delved deeper and found that everybody and their dog had done ‘Will You Love Me Tomorrow,’ ” Rogan said. “But I’m like ‘OK, doing the song the way I’m doing it is, in fact, breaking new ground. Yeah, big, fat horns. Let’s do this.’ ”