Ike and Tina. Noel and Liam. Axl and Slash. Like those other classic onstage couples, Fitz and the Tantrums vocalists Michael Fitzpatrick and Noelle Scaggs are known for having a mercurial relationship. “You don’t know whether we’re going to kiss or hit each other,” Scaggs says with a laugh.

That’s just the way they like it. With the male/female duo out front, the dapper-dressed six piece has made a name for themselves, as much for their fiery live shows as for their addictive, modern take on ’60s R&B.

“There’s just always been this really cool, intense passion between us,” Scaggs says. “Since day one at the first rehearsal, Fitz and I have had a real chemistry in performing with one another. It just happens naturally. I think that’s never going to go away.”

How much of that passion is real, and how much is an act? That’s tough to say. But for Scaggs, that lover’s quarrel tug-of-war is just a natural extension of the music. Take “Moneygrabber,” their 2010 summer hit that catapulted the band to the forefront of the soul revival scene, right up there with Cee Lo Green and Sharon Jones and the Dap-Kings. It’s easily one of the funkiest, ass-shakingest kiss-off songs ever put to tape.

So it will probably come as no surprise that Fitz and the Tantrums was born out of a particularly nasty break-up. Four years ago, mastermind Michael Fitzpatrick (whose friends call him “Fitz”) was a heartbroken 38-year-old working at an L.A. recording studio. When his actress ex-girlfriend called him up out of the blue, he was this close to ignoring the call. He’s damn glad he didn’t.

She was calling to tell him that her neighbor was moving out and selling a rare, old church organ. A few hours and $50 later, that organ sat in Fitz’s living room. He pulled up a chair and fiddled with the keys. Within five minutes, he was so inspired by the old-school sound of his new toy that he wrote what would soon become the band’s first single, “Breaking the Chains of Love.” The blue-eyed soul of the melody surprised even him, but after years in the music industry, he knew not to question a good thing.

To capture the full, rich sound he was hearing in his head, though, he needed a band. Like Otis Redding and his other Motown heroes, Fitzpatrick envisioned a saxophone, organ, and tight rhythm section driving the music more than guitars. And, most importantly, he wanted a female co-vocalist, a harmonic counterpoint, a person that could play the sultry yin to his Bowie-cool yang.

A friend gave him Scaggs’ number. Like Fitz, she was also an industry veteran. A powerhouse singer, Scaggs spent years fronting the popular L.A. jazz-funk band the Rebirth. She’d also contributed backing vocals to a slew of other artists’ albums, most notably Elephunk by her good friends the Black Eyed Peas (you can hear her vocals on the Grammy-winning track “Let’s Get It Started”).

Fitz sent Scaggs a demo. The first thing she was struck by was how familiar it sounded. Growing up, her father used to DJ after-parties for R&B dance groups like the Whispers, so at an early age, she was introduced to everything from Parliament and the Temptations to early Teena Marie and the Pointer Sisters.

“We used to have a lot of vinyl in the house,” Scaggs recalls. “So when my parents were away at work, I’d come home from school and throw on a record. I’d try to learn as many of the words as possible and the phrases and how they sang things.”

But what really sold Scaggs on the project was not the pleasant memories, but the uniqueness. Behind that Motown/Hall & Oates-vibe, she could hear hints of ’80s New Wave and “this really cool, hip-hop swing.”

Scaggs was in. But with little money and no backing, the band was forced to record Pickin’ Up the Pieces, their breakout debut, almost entirely in Fitz’s living room. Looking back, the 32-year-old Scaggs is amazed they made at all.

“I couldn’t pay my bills. None of the band could,” she says. “And we were wondering if this was going to work or not. Like, you go through all those trials and tribulations of a band. But we’re no longer 20 years old where we can crash on our friend’s couch or stay at our moms’, you know? We’re grown-ups. What are we doing?” She laughs. “But we took the risk that we needed to in order to get to where we are now.”

Which is a pretty nice place to be: headlining sold-out shows across the country, playing Conan and Leno and Fallon, hanging out at Daryl Hall’s house. Currently, the band’s hard at work on their follow-up album, this time in a real studio.

“It’s definitely expanding on what we’ve done,” she says about the new batch of songs, a few of which they’ll be playing at this week’s show. “We wanted to keep some familiarities, because you never want to go so far right that your fans can’t figure out where you’re going. So we’re broadening the horizons, while still keeping the integrity of who we are as a band.”

But really, the band has only one thing on their minds. “Our main focus is creating and crafting great songs,” Scaggs says, “making sure that we’re creating something that will stand the test of time.”

Now that sounds like true love.