He is writing songs with Lewis Capaldi and swapping sweets with Teddy Swims, but anyone wanting to listen to rising pop star Kerr Mercer’s music has a problem – because he hasn’t released a song yet.

The Lanarkshire singer’s piano-led songs have seen him sell out gigs across the country and earn support slots with major bands.

But he’s decided to wait before bringing out any music so he can “build a real fan base”.

“I just find it insane that people are wanting to come see me without any music being out,” admits the teenager, who is from Uddingston.

However, his unusual approach hasn’t stopped him being backed by Lewis Capaldi, who has worked on a tune with the 18-year-old.

The duo share a management company – Interlude Artists – which helped set up a collaboration between the two.

“Lewis has been absolutely class with me,” he told BBC Scotland News.

“We met a few times and have now written a song together. When I was starting out I was covering his songs and now we’re writing together – it’s a bit mad to have people at that level interested in what I’m doing musically.”

Other than video clips shared on social media, no-one can hear Kerr’s sensitive piano-led songs – a deliberate decision.

“I’ve seen so many artists on TikTok firing out a song a week but then not be selling out 200-capacity venues”, he explains.

“I’d rather sell out a tour than have a million streams on Spotify. One thing that’ll never change is that real people want to go see gigs so I’ve just done lots of shows and supported folk.

“We did two headlines in Glasgow, selling out King Tut’s. Then it was Saint Lukes, which is double the size of Tut’s, and then a UK tour. I spoke to a few people and decided to try to push it out further with another tour.”

He jokes most of the people coming to those gigs are family members, which plays down his growing popularity.

However, he has had plenty of family backing, taking singing and piano lessons as a child and getting a taste of the arts by appearing in pantomimes as a youngster, treading the boards at the Pavillion theatre.

It came naturally to someone who admits he was “always the class clown” at school, and enjoyed being the centre of attention.

By the age of 10 he was singing at a local song club, performing a Queen track on his first appearance.

His musical roots come from the school run, however.

“I was in primary school in Uddingston and my sister was in secondary at Uddingstoon Grammar, so I had half an hour to wait before my grandad picked her up. He had a Sam Cooke record that would just play and before I knew it, I had all the words off by heart.”

That led to a love of classic soul – Otis Redding, Ray Charles, Etta James – that Kerr says is “imprinted” in his music to this day.

While he can’t credit his family with blessing him with musical genes (“there’s not much music in my family other than karaoke” he laughs) that hasn’t stopped parents Kirsty and Robert offering support.

And in his mum’s case, some criticism…

“I could do the Brits and she’d tell me if I wasn’t good,” he says.

“As soon as I write a new song I’ll send it to my mum and dad first. My dad is chill, he likes everything but me and my mum are very similar, so if I’ve not done my best, she’ll tell me.

“I’ve played to thousands supporting Tom Walker and my mum was like ‘you weren’t at your best tonight’ but then other times she goes ‘that was outstanding’.

“More people are now telling me everything’s going amazing but I only believe I’ve done well if I get the seal of approval from my mum.”

He has been backed by far more than his family now, having racked up support slots with a number of pop music heavyweights like Teddy Swims and Myles Smith.

The advice of Stargazing singer Smith – the man with the best-selling British single in 2024 – has provided a big boost to Kerr, even if those words of wisdom are sometimes delivered tongue in cheek.

“I was home for Christmas and not sure what to do now that the tour was over. I got a message from Myles that simply read ‘why don’t you release a song, ya melt’.

“He’s great though. It’s not like the support act is always chilling with the headliner, but Myles was amazing about it. I was sitting in my dressing room and Myles burst in and was like ‘why are you here, come have a beer with us’ – then we would just sit talking about songs.”

He’s now writing with an array of collaborators, and starting to record material with the aim of finally releasing songs later this year, adding that he’s being a “perfectionist” about what should come out after such a wait.

“It’s great fun too – you go for a day, write a song together and then go to the pub. There’s not many jobs where you get put with two people you’ve never met, have a therapy session and then write a song about it.”

Among his new colleagues include Luke Pritchard, the singer with indie veterans The Kooks, while on the production side he’s been helped by producers and engineers who’ve worked on releases by the likes of Ed Sheeran and Adele.

Despite his young age, the singer says he’s just trying to relish everything as it happens.

“I was watching the Grammys and Teddy Swims was on – I’ve been eating wine gums in his dressing room with him.

“I’m just loving every minute – even if it ends tomorrow at least I’ve had a blast doing it.”