Today, Monday, Peter Kelly has a new album out.

Called Darling Darkness, it's his seventh - the second recorded in a studio - all released under the name Beerjacket. If you've not heard any of them then you may have seen him supporting the likes of The National, Throwing Muses' Kristin Hersh or Feist. Or maybe you caught him on The Review Show on BBC2 or heard him on the Vic Galloway Show on the radio.

In short, he's been a busy boy and music is what he does.

Today, Monday, while digital data streams of Darling Darkness are downloaded on to iPods and mobile phones, Peter Kelly himself will be in class teaching English. Because that's what he does too.

I've been wondering are the musician and the teacher different people? I finally get to ask him, the two of us sitting discussing music and fame and the rewards of education in Glasgow's Cafe Hula. "I'm not a different person anywhere," he says. "That's a really unhealthy way to live."

Kelly is not, he explains, a teacher because the music hasn't taken off. He's not a musician because he needs a creative outlet from the day job. Both roles are central to who he is, he says. Who Peter Kelly is, it turns out, is a fiercely articulate conversationalist and a born multi-tasker. A musician, a teacher, a husband, a father of two young children, his own manager, label boss and publicist. He's even the cover artist of his own CD. "I'm quite organised and I'm creative as well. There are certain people who think being disorganised is part of being creative and I'm quite the opposite. I'm really functional. I'm hyperfunctional."

How does he do it all? "I'm awake a lot. I never really drop the ball with anything in my life. If you care about things you get them done."

And anyway, he says, nobody could care about his songs as much as he does. He worries that industry representation might lead to things he disagrees with. "Would somebody do the wrong things because it was going to make more money? If somebody sees your song is attached to an advert and it cheapens the song or it changes the associations of that song then that is out of your control and ultimately if you're taking any financial credit it's dirty money, isn't it?"

Is it? He wouldn't take money for an ad at all then? "It would depend what it was." What about one of his songs being used in an HBO drama, say? "Well yeah, that's quality though." He pauses. "I just think it's interesting how much music has become such a commodity and I wonder if part of the reason for the fact that people don't seem to spend as much money on it now is that seems to be the way it's designed. Without being a hippy about it, would Bob Dylan have thought 'this would work with washing powder?'"

It's such an interesting point I almost don't want to remind him that Dylan has already sold his songs to Google and even turned up in a Victoria's Secrets ad once. "Oh heck, maybe everyone's chucked that idea."

Kelly is proud of his new album; so much so he can even listen to it, "but you have to curb it because you can't turn into a narcissist". Better than that, he's heard his two kids, who are just four and six, singing along, not knowing they are the inspiration for some of the songs. "Without wanting to be cheesy, there's a sweetness to that that's pretty hard to be hard to."

Listening to it, I tell him it made me think of Roddy Frame's solo album Surf. "People have mentioned him for years. I need to listen to him. I've never listened to him."

Perhaps because Kelly is of a different generation. He's 35 now, grew up - in Airdrie and Coatbridge - on a diet of grunge. He was in a band by 14, signed a publishing deal by 16. Who was this very driven teenager, I ask him? "Just moody, very clichéd. The teenage stereotype. 'No-one understands'. I've got a bit of affection for that 16, 17-year-old self who thought they were the only person in the world who liked Nirvana and was angry."

What did he want from life back then? "I really wanted to be the cliché. The musician in the music industry and being famous." Presumably his idea of fame then was different than it was now. "I think the pursuit of fame back then when many of us felt it ... Maybe that fame was a different beast than the one it is now. I suppose I would have wanted to be a Kurt Cobain, obviously with a happier conclusion. But I don't want a conclusion at all. I wanted to create things that meant something. But even the concept of meaning is a very teenage one. That's self-importance. I'm an only child so I guess it's not entirely my fault. It's embedded in my being."

He thinks that his teenage concept of fame has more or less gone now. A good thing. "It will save a lot of teenagers a lot of heartbreak. Because it's painful. It's painful to let go of a dream. But the older self would tell you you're not really letting go of anything that means anything at all. My children are more of a dream than being a famous rock star in the 1990s.

"I think it's something that takes a long, long time to understand, but being an adult for all its trials, all its mundanity, is actually a gift. Being an adult and having wisdom. I would never be disparaging to a young songwriter but I know my own songs when I was a teenager and even from my early 20s were hideous, empty holes which could have been filled by experience had I not been too busy trying to pretend I already had it."

When does he think he grew up? "I found it really liberating when I started doing this by myself. I was 24."

He got married around the same time. That helped too, he says. "That was the first step in growing up and having a direction in life. Art is only useful if it's in parallel with life. I think it's horribly self-destructive if you become artistic rather than a functional human being."

He started teacher training in 2001, started teaching a year later and has now been a fixture in the same Hamilton school for about a decade. When he talks about teaching he glows with the rewards it offers. "I love when pupils do well but there is something beyond that. Just the idea of them engaging with the thing that you love. You can transform a piece of writing from black and white on a page to something that could colour their perception of the world, of life. That's incredibly special."

It's why, he says, he gets angry that every time he does an interview about music he's asked if he'd give up teaching if he became successful. "It's as if people implicitly think I'm a failure because I won't give up my job. I love every aspect of my life. I wouldn't give up any of it. I'm such a lucky man and I know it as well. I'm almost embarrassed by my fortune."

That's not a monetary definition of fortune, is it? Peter Kelly is lucky enough that the rewards of his life are reward enough. Before he goes back to that life he tells me a story about a secret gig he did in Edinburgh with his hero and friend Kristin Hersh, singing Your Ghost, a song he sang on his 16th birthday with her. "Kristin has to take out her contact lenses.It's an intense performance when she plays. It looks like she's staring right through you. She just can't see you. She's blind without her contact lenses. She asked before I came up to sing Your Ghost with her, 'Peter will you hold my contact lenses?' Actually she said 'will you hold my eyeballs?' She's got an interesting way of talking.

"If I could have explained to that teenage me that, yeah, I did go and be a teacher. Yeah, I did give up the dream of touring and trying to be famous ... But I shared a stool with Kristen Hirsh and I sang Your Ghost holding her eyeballs, I think he would understand."

Today Peter Kelly is a musician, a teacher, a father, a husband. Today Peter Kelly is who he wants to be.

Darling Darkness is out today. Visit beerjacket.bandcamp.com/ for details.