With their old school soul sound, St Paul and the Broken Bones burst onto the music scene in 2014.

It would have been the easiest option in the world for the band to make more of the same for their second record – but frontman Paul Janeway reckons he’d have scrapped the whole band if they’d settled for repeating themselves.

Instead they made Sea of Noise, a darker record that adds strings and a sense of sadness underneath their uptempo, brass-powered tunes.

“We felt like we were making Half The City part 2 and that wasn’t really something we were comfortable with,” says Paul, prior to the band hitting Glasgow on Sunday for a sold out Celtic Connections show at the O2 ABC.

“I would have probably quit doing this had we done that because it just wasn’t scratching that creative itch. Once we took a deep breath we found where we needed to go… As far as writing goes I had more time to really think about the lyrical content. That was really important to me because I didn’t have that kind of time with Half the City.

“I love the strings, too. To me the strings bring a darker tone to a song. It is a sad beauty (on the album).”

Half the City’s success came as a complete shock to the band, who were formed by Paul and Jesse Philips back in 2012. At the time Paul was considering a career as a bank teller, but decided to give music another shot. Soon they’d formed St Paul, a live act who whip up a storm with their soul, with Paul displaying his powerful rich voice whenever he can. Early attention focused on the fact Paul had originally considered life as a preacher, but the release of debut album Half the City showed they were a group that was here to stay.

Sea of Noise is another step forward, with Paul taking lyrical inspiration from the book Just Mercy, about the flaws within the American justice system, and a sense of trying to hold onto things while everything is collapsing around you.

“I was very deliberate in certain thematic elements and others happened more organically,” he says.

“I thought the music hides the real intention of the lyrics so the darkness and bleakness would be overlooked if the listener wasn’t really paying attention. Just Mercy inspired me to be a better person. It prompted me to explore my southern identity in these modern times and it was definitely a different route for me to go.”

The band also head into the studio emboldened by touring the world. Their live shows earned so much praise that they caught the attention of the Rolling Stones management, who invited them to support Mick, Keef and company on several shows in 2015.

However opening for a band like the Stones can come with pitfalls, because audiences at huge shows can often have no interest in a support band and just want the headliners. That’s a test that Paul was happy to take head on.

“I loved it,” he enthuses.

“We were warned that the audience wouldn’t pay attention and I just took that as a challenge. We got standing ovations each night so I consider it a success. It was an incredible honour and something I will never forget.”

Another honour for the eight strong group is getting to tour the world. They’ve been able to visit numerous different places, something that the frontman loves.

“There are so many amazing moments and places we get to go,” adds the singer.

“On this tour we just did Stockholm and it was our first show there. It was a sold out room and those people were going crazy for every song. I feel very fortunate to get to do this with people I love.

“I remember the Glasgow crowd being a rowdy one before. It was a ton of fun to do.”

And although it’s only been a few months since Sea of Noise was released, Paul is already looking to another album.

“We are well beyond anything we thought,” he says.

“I actually still having the writing bug, so I will probably start writing the next record soon.”

St Paul and the Broken Bones, Sunday, O2 ABC, sold out, 7pm

JONATHAN GEDDES