Eugene Kelly wants to talk about karaoke. 'It's good to just get up and belt out a song', he tells me with warm enthusiasm, 'and to do something that stretches you. When you're writing it's easy to stick to the same range and structure.' Like any performer worth their salt he's got a go to anthem; Shirley Bassey's 'Goldfinger'. 'I go for big things', he adds.

The Vaselines were never asked to write a Bond theme (and more's the pity, really) but the project formed by Kelly and Frances McKee grew far beyond where either could have imagined. 'I think we were a comedy act really,' he says, reminiscing of the early days, when the two met as Glasgow schoolchildren. 'The songs were about us amusing each other and making each other laugh. We knew our limitations, and the limitations of where our music could go – that's pure. You're not thinking "this will sell a million", you're not thinking there's any chance of a record deal, you're just doing it to laugh, to pass the time when the TV's not on.' Of course, Kurt Cobain found out about The Vaselines, and their music was destined to reach millions. Even today's 10 year old kids are uploading covers of 'Molly's Lips' to the internet.

But The Vaselines had all but split by the time Cobain championed them – as a couple and as a band, they were done before the release of debut album Dum Dum in 1989. By the time Nirvana did their third Vaselines cover – 'Jesus Don't Want Me For A Sunbeam' – for their MTV Unplugged performance in 1994, five years had passed. Having reunited for a handful of shows in the mid-noughties, the band returned to their old label Sub Pop for their second full-length Sex With An X in 2010. But after 2014's self-released V For Vaselines, they gave serious consideration to calling it quits for good. 'If you put records out yourself,' Kelly says, 'finance it, and it doesn't make money back – then you don't have money to make another record.' Opening for their friends Mogwai at the Barrowlands seemed a good way to bow out.

'We pretty much thought it would be our last show,' Kelly says. 'We played it like it was our last show. We gave it so much effort and came off thinking "we've gone out on a high". But off the back of it we got asked to do a headline show at Summerhall in Edinburgh, and then offers kept coming and coming. We kept thinking "this will be the last one" – there was a lot of sweat and screaming, Springsteen style. It came to the end of 2015 and we just thought "we'll not say we're splitting up", we'll just see what happens. We're not planning on writing another record, though'.

The Vaselines are a headliner at this year's Jupiter Rising festival; with Kelly excited about the maiden event's eclectic bill. 'It's great to be asked to do things like that, an arts festival in an outdoor gallery with lots of interesting people. It's an odd thing for us to do – we hardly do festivals of any kind – but it'll be really good.' Beyond that, Kelly's got the same urges he ever had; to create and to get out of the house.

'I do miss touring,' he says. Frances doesn't as much, she's got children and got a yoga business, but I really like touring. I've spent my entire life in Glasgow, I get really frustrated after a while being in the same place. I go on a train sometimes just to feel myself moving, I go on my bike just to feel like I'm going somewhere. I can't just sit here forever.' He's been working on a solo record for a while now, filtering through around some 300 ideas. 'I write lots of rubbish,' he says, downplaying his talent with the signature self-deprecation that's never far away during our conversation, 'but find one thing that's worth turning into a song,' he says.

There's another project to look out for too, from a man who's written a few songs for theatre productions. 'I was watching the news the other night and there was something about a theatre production of Local Hero. Ten years I woke up and had the idea for Gregory's Girl: The Musical, and I wrote it down, and said to my flatmate "what do you think of this?" I watched the film and there's a song here, a song there; a song when he borrows the coat and goes on the date – I've got that one finished.' With that, Eugene Kelly heads home to write Scotland's next great musical, though he cautions us about getting our hopes up. 'I'm all talk. I've been saying the same thing for five years.'

The Vaselines play Jupiter Rising on Fri 23 Aug. Find out more and buy tickets at jupiterrising.art.