There are many things to discuss with Ben Folds, but there’s a serious accusation to be made too.

Recently the 48-year-old was pictured on Twitter wearing a Justin Bieber T-shirt - could it be that the piano playing singer-songwriter is an admirer of the often ill-behaved pop star?

“It’s my daughter’s shirt, and I just had it on as a joke,” he chuckles. “She took a picture, although it took about four tries to do it without me laughing. It’s my job to let people know I’ve got a record coming out, but everything went nuts online after I put the Bieber T-shirt on.”

Folds is in cheerful, good-natured humour here. He has evident enthusiasm for the actual purpose of our chat, his new "chamber rock" album with classical sextet yMusic. The record, So There, isn’t out until September, but Folds will bring it to the Kelvingrove Bandstand in Glasgow next week for a show as part of the Magners Summer Nights season of concerts.

Originally he planned to make an album working with various chamber orchestras, but plans changed when he was introduced to members of yMusic, and over four sessions So There took shape. What also changed was Folds mind-set when writing.

“I never really love the process of writing, it’s something that I put off a lot,” he explains. “This time I disciplined myself more than normal, partly because I was working with these amazing musicians and I needed to feed the beast. Writing is a funny thing and there doesn’t seem to be a magical recipe for it.

“I’m in a pretty reasonable headspace just now, and sometimes that can really f*** someone’s writing up, so what’s the balance? But for me it’s a good thing - I’ve done plenty of writing where I wasn’t all that balanced, where I wasn’t having a good time, and that’s been good stuff too. But I found a lot of strength this time.”

Some of those harsher times have been evident on his work - the Nashville singer’s third solo album, Way To Normal, had a particularly bitter streak running through it. Several years later, he appears to have finally found a more normal routine.

“I’m 49 pretty soon, and you’ve got to start maintaining everything, including your sanity,” he explains. “It’s like how you maintain a car or something. You don’t have to go all LA and have three therapists and a juicer and that, but it’s good to have things in mind like ’I’ve got two days coming up and I need to accomplish this’.

“There’s a million ways to cut it up but basically it’s feeling more normal, which for me made for a lot less static when I was writing songs.”

That also led him to classical music again. Folds has regularly played with orchestras over the years (including when in Scotland) so a record was the next obvious step. So There uses orchestral ideas, but built around pop and rock, and Folds feels just now is the right time for a project like this, coming on the heels of spending the past couple of years reuniting with his old band, the Ben Folds Five.

He speaks of a lack of innovation in modern music, save hip hop.

“I couldn’t have done this five years ago. I’d have got slaughtered for it, but now people are listening… It’s hard to keep hip hop and R n’ B from innovating, so there’s always that, but there’s interest in classical music because people are waiting for something truly new to happen with pop, which hasn’t happened in my lifetime.

“I was born right after the Beatles took things from Frank Sinatra to psychedelic - since then, there’s been disco and Nirvana and hip hop, and that’s been about it.”

Ben Folds plays the Kelvingrove Bandstand on Friday August 14 as part of Magners Summer Nights