Sibling singers the Oh Hellos have a new album inspired by literary great C.S Lewis.

But the duo have an even bigger inspiration fuelling them – the Muppets!

“The Muppets are a ragtag band of misfits who come together in spite of their differences in pursuit of a simple dream, to entertain and encourage,” explains Maggie Heath.

“They're warm, funny, smart, and never take themselves too seriously so it's inspiring to us! We want to be just like them when we actually grow up. As far as our favourite Muppet goes, it's a hard choice, but Tyler says Gonzo and I’d say Rowlf.”

Maggie and Tyler are set to play their first ever Glasgow gig this weekend at the CCA. The Texans originally collaborated to make a jokey song for their mum, and ended up sticking together to perform more serious stuff, combining their vocals and harmonies with a clutch of great melodies and an impressively thick folk-rock sound.

They have also knocked back any big label that’s approached, preferring to work as an independent act, despite early single Hello, My Old Heart earning them plenty of radio airplay and offers.

“We like the freedom to do things however we want,” says Maggie.

“And early on, we didn't want to get too tied down to music as a career, just in case we decided it

wasn't for us.”

Given that they are now onto their third album with this year’s Dear Wormwood a lengthy career is looking likely. The record’s title is lifted from a character in C.S Lewis’s The Screwtape Letters, which takes the form of a series of letters from a demon to his nephew, discussing the damnation of a man.

It’s a book that has fascinated the duo for years.

“It offered a unique perspective on a lot of theological subjects, which really encouraged us to think critically about our own beliefs,” says Maggie.

“Setting that aside, though, it's also very encouraging, in a backwards sort of way, and a really entertaining read.”

As with the rest of C.S Lewis work (such as the Lion, the Witch and the Wardrobe) the book has heavily Christian themes, something that’s true of some of the Oh Hello’s songs. The duo believe that their background growing up as church-goers feeds into the ideas behind their songs, which touch upon reflection, redemption and resurrection.

“We grew up in church, and that's definitely stayed with us as we've gotten older and become a part of who we are,” adds Maggie.

“Our goal in writing music is just to be ourselves, and write songs that mean something to us, and hope that maybe some part of them will resonate with anyone else who listens, too.”

However the biggest theme running through Dear Wormwood is trying to escape a terrible relationship. How much of that is based on their own experiences?

“There are bits and pieces that came from our own lives, but it's based less on firsthand experience and more on what we've observed in the people we're close to,” says Maggie.

“It’s relationships that friends or family members were too deeply involved in to see clearly.”

Now they’re keen to bring the album to Glasgow. While Maggie and Tyler record everything on their albums themselves, their live gigs see them joined by as many as 13 other musicians depending on the occasion, helping beef up the sound (Saturday isn’t likely to see quite that many onstage).

Switching from a small set-up to a much larger one creates a few hurdles.

“It presents us with challenges and limitations, but the energy, enthusiasm and camaraderie of so many musicians all performing together at once is something we can't imagine giving up.

“In the studio, we put as much feeling and intensity into the music as we can, but when we bring it to the stage, it feels right.”

The Oh Hellos, CCA, Saturday, £13, 7pm