Image copyright Columbia Records Image caption Declan McKenna signed his record deal amid the mud at Glastonbury

Seventeen-year-old Declan McKenna has emerged as a fresh and intelligent voice in indie-pop, unafraid to tackle the big topics.

His breakthrough single Brazil addressed how construction work for the 2014 World Cup destroyed dozens of local communities.

Last year's Paracetamol was inspired by the story of Leelah Alcorn, a transgender teen in Ohio, who committed suicide after being sent for Christian conversion therapy.

"I just didn't realise that stuff like that was still going on," says the singer, who grew up in Hertfordshire.

"Recently, we've had the bathroom bill and all these sorts of things. I wanted to write something against that."

Media playback is unsupported on your device Media caption Declan McKenna performs Paracetamol in session for BBC Music Introducing

McKenna got his big break when he won Glastonbury's Emerging Talent Competition in 2015, and signed his record deal at the festival later that year, knee-deep in mud.

Since then, he's released a series of singles tackling religion (Bethlehem), xenophobia in the media (Isombard), and being part of a voiceless generation (The Kids Don't Wanna Come Home).

Crucially, they're all fizzing alt-pop concoctions that never patronise or preach - they simply get on with the business of being top-notch indie anthems.

He's just announced his debut album, What Do You Think About The Car, which will be released on 21 July - and was overseen by producer James Ford (Arctic Monkeys, Florence + The Machine, Foals).

Ahead of the release, McKenna sat down to discuss his inspirations, being patronised by the press and his penchant for dungarees.

Why is your album called What Do You Think About The Car?

It's from a home video when I was four years old. We'd just got a new car and I was stood in front of my grandma's house. On the video, my sister goes, "Dec! What do you think about the car?" And I go, "I think it's really good, and now I'm going to sing my new album!"

That was my first reference to making an album - and we've sampled it on the record.

So you've been planning this ever since?

Yeah! I mean, at the end of the video, I start singing a Busted song. I don't think I knew what album meant, but it's just a really funny, cute thing about my roots and where it's all come from. It just made sense.

What were your early songs like?

Not very good! There was about two albums' worth of demos online before I released Brazil - which I took down soon after. I was trying to be Sufjan Stevens but on the most basic music software you can get. I was trying very hard. They're... erm, interesting.

Media playback is unsupported on your device Media caption Declan McKenna performs Brazil in session for BBC Music Introducing

What prompted you to send Brazil in to Glastonbury's Emerging Talent competition?

I'd been entering competitions forever. It just so happened that this was the one that got picked up - which was awesome because obviously Glastonbury is an enormous festival.

How did you find playing there?

I was pretty young, I was 16, so it was just unreal. I played the shows and got signed to Columbia Records there as well.

Really?

Yeah, the guys at Columbia said, "Let's sign at Glastonbury," because it was more exciting than doing it in an office or whatever. And then we just went out and had a bit of a party.

So you have a legally-binding contract that's completely covered in mud...

Well, it was raining at the time! I think they kept it in in some foil or something, and then it was taken out for 10 seconds, like, "Sign this! Sign this!" And then it was done.

A lot of your singles deal with serious topics. What led you down that path?

I think, primarily, just not having much to write about! I was in school, I didn't have a girlfriend, I didn't have anything going on, really, except exams.

So that's what pushed me to write about stuff that doesn't necessarily impact me directly, but which I think needs to be talked about.

Media playback is unsupported on your device Media caption Declan McKenna performs Isombard on the BBC Introducing Stage at Radio 1's Big Weekend 2016

I read a lot of articles where the journalist seemed surprised someone your age would write about such serious subjects. That's quite condescending.

Yeah, I think so. A lot of the stuff I'm talking about is politically engaged, but I'm not by any means the most articulate or intelligent young person I know. There's nothing exceptional in talking about these things. I just do it and I put it in pop songs.

Kids Don't Wanna Come Home is an interesting song. You're both cynical about the state of the world and optimistic for it's future.

Yeah, 100%. It's about wanting to be part of a powerful and intelligent young generation - who stand up against these negative things we're shown incessantly on our phones. There's a lot of confusing information out there - but I'd like to be hopeful in a world that's often thought to be in despair.

Were you too young to vote in the referendum?

I was.

What did you think of the result?

My friends and I were, to a fair extent, ticked off.

I wouldn't have voted in favour of Brexit if I was able to vote. Now I'm 18, I feel just as informed now to make a decision as I was a couple of months ago.

Just on a personal level, as a touring musician, it's going to be a pain in the arse.

Image copyright Columbia Records Image caption The teenager has been playing guitar since he was nine years old

Musically, who's the gold standard? Who would you like to emulate?

David Bowie.

Yeah? Wow! That's a lofty goal.

I mean, you have to try and make the best music you can, and you're not going to do that by emulating something you don't believe is the best. And I think David Bowie's music, in a lot of senses, is the peak of music.

Obviously, I don't think I am as good as him but I'd like to be. I'd like to be able to make something as good as Hunky Dory or Young Americans.

Which Bowie album are you on the level of right now?

Probably none of them. Maybe Earthling if I'm lucky. I don't think it's my favourite Bowie album by a long stretch but it's still there, it still deserves a place in my heart.

Finally, I have to ask about the dungarees. You've been rocking them for a while now...

I just like a good pair of dungarees. It's comfortable, it's versatile, it looks good with anything. I'm a fan.

And there's a handy pocket at the front for snacks.

I've got loads of pockets. Pockets galore - that's my nickname on the street.

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