Paul Janeway sings like he’s got nothing to lose — or, perhaps more correctly, like someone who’s lost a lot and lived to tell it all. Of course, the truth is, he gave most of it away.

First, there was the life of a pastor, having grown up in a Pentecostal-leaning church. Then there was a second career, when Janeway decided that preaching wasn’t for him, at the bank. Both were certainly reasonable life choices for a young man in the American Southeast.

Instead, Janeway decided to became something as improbable as it has been rocket-ride successful: A grease-popping soul-singing sensation. Performing along with a quickly formulated group of like-minded Birmingham, Alabama musicians, Janeway is now running the roads as St. Paul and the Broken Bones. Last October, the group — which also features trumpeter Allen Bransetter, trombonist Ben Griner, drummer Andrew Lee, guitarist Browan Lollar and bassist Jesse Phillips — performed some 24 shows over just 30 days as they laid groundwork for the 2014 release of their long-playing debut, Half the City.

Mentions in Paste, Southern Living and on NPR followed. But it all started with a visit to South by Southwest last March. This wasn’t a valedictory trip, however. St. Paul and the Broken Bones had no record deal, no booking agent. They didn’t even have an invite to, you know, South by Southwest. They just went. Well, after Janeway parted ways with the bank.

“My place of employment was graceful enough to let me quit,” Janeway tells Popdose, “instead of firing me — so I could say that in interviews (laughs). It’s probably the best decision I’ve made, but it was risky. That was very scary for me. I didn’t think about it much at the time, because I was so involved. But I think most people would have told me that was pretty crazy.”

Perhaps owing to that gutsy move, St. Paul and the Broken Bones’ new R&B-soaked 12-track project, due on February 18 via Single Lock/Thirty Tigers, has an unironic, throwback quality — and a deeply emotional underpinning. They take this work very seriously.

“I’m not smart enough, I feel like, to use symbolism and metaphors, and shit like that,” Janeway says. “For this, it was a direct, straight-from-the-gut type thing. Using ‘I’ and ‘me,’ things like that. It definitely from a very, like, personal level.”

In keeping with his front-pew upbringing, Janeway’s performances often recall a canny melding of Al Green and James Brown, but his persona — both in the quirks of the lyric writing and even in some of Janeway’s mannerisms — can pull in the shambolic idiosyncrasies of Tom Waits, as well.

Janeway’s musical history, it turns out, is a complex as his personal one. He even picked up on the raw confessionalism of early U2, along the way. “That was one band that provided a transition from gospel, Christian music,” he says. “I know that sounds strange, and I don’t even listen to U2 now. But Bono was definitely somebody I listened to as a singer. That was one that is definitely a little bit out of left field.”

As the venues have quickly grown larger, Janeway has had to call on all of those myriad influences. “I think we’re still trying to adjust to that,” he says. “I don’t have a huge problem with it, because I have a tendency to get out into the audience. I do get a little more winded now, though, than I used to. (Laughs.) For now, I think everything has translated pretty well.”

Half the City, which follows an earlier EP, was produced by Alabama Shakes’ Ben Tanner in Muscle Shoals, Alabama. Like the band itself, everything came together quickly — and yet it fit together perfectly, too. The songs feel loose at times, but never tossed off. They’re reminescent, in that way, of lightning-in-a-bass amp moments like Booker T. and the MGs’ “Green Onions” or the Staple Singers “I’ll Take You There.” Experience, not spread-sheet planning, brought them to this place. Feelings, not thoughtful ruminations, did the rest.

“It’s funny — we did something a little strange,” Janeway says. “I’d say 75 percent of the record was written in about a month. We just had to capture whatever is going on here. And that’s what’s really interesting, when I listen to the record now. I go: ‘Man, whatever that moment was, we definitely caught it.’ Of course, we play the songs all the time now, so we feel like could play them so much better now. But, at that point, it was just something very raw.”