Born in Glasgow and raised in Whitburn, West Lothian, Lewis CapaldI arrived in 2017 with his debut single 'Bruises', which racked up Spotify and YouTube plays in the millions, and earned him a major label deal and a tour support slot with Rag 'n' Bone Man. Now the 21-year-old is on this week's BBC Sound of 2018 longlist, which is the first place he saw Frank Ocean mentioned when he came second back in 2012; these days he works with Ocean's producer Melay, whose other regulars include Sam Smith, Lorde and Zayn Malik. We spoke to him before Christmas.

The year 2017 was good to you, wasn't it?
Every year I would wake up on the 1st of January and think, 'this is the year it'll all happen,' and it would become increasingly pie-in-the-sky. But this time it all seemed to come together as soon as I released 'Bruises'. Before 2017 I'd never been on a long haul flight before, I'd only been to places like Ibiza and Magaluf on holiday, and now I've been to Hong Kong, America, all over Europe... I don't think we've put on a show this year that hasn't sold out, and all the ones (in 2018) are going to sell out too. Doing a festival in Hong Kong was special, looking out and seeing this massive crowd and the city. TRNSMT as well, I always used to go to T in the Park, and seeing how many people came out for it was great. I went to America for the first time as well, and to visit these amazing offices in skyscrapers on Times Square, it was a great perspective. And I loved hearing people singing the words back to my songs as well, the first time they did that with 'Bruises' was at the Mash House in Edinburgh, the first place I'd played a proper gig six years earlier.

How did you get started in music?
I was born in Glasgow then moved through to Whitburn. My brother started playing guitar, and I said 'if he's getting guitar lessons, then I want guitar lessons too'. He's six years older than me, so when I was about twelve he'd be in bands and I'd think, 'if he's doing that I'll do it as well', and I'd copy him. I played my first gigs around the pubs of West Lothian, and it always felt like a hobby, but the way I actually got from there to here was pretty seamless. I would have been happy teaching music in schools - I still would be and I still might be, although I don't know if I'm clever enough. But I basically wanted a career in music either way.

Did you want to become a music teacher?
I don't know if it was my main ambition, but it was one of the roads I was looking at. I did my HNC and my HND at college in Motherwell, and the plan I had was to do third year at uni and then to try and get into teaching. Then in second year of college I met my manager (Scott Kirkwood, who manages KLOE) and started going down to London. I still finished college, but the last couple of months were pretty strenuous, considering how much I was away. I know I've deviated from the path slightly, but I've got no complaints so far.

Can you remember the moment you knew you were getting somewhere?
I'd been in my own wee bubble, writing every day, wondering if anyone was ever actually going to hear the music. It wasn't until early this year, January or February, that people started to wonder what this Capaldi guy is up to; I was doing work with other writers and producers, and obviously those circles are small, so people were talking to each other. When we put out my first single in March, that was the first time I thought, 'oh shit!' It was number one on New Music Friday US on Spotify, and I don't think my manager's phone or email has stopped since. Literally that night, it was decided we had to go to America within a couple of weeks and meet labels. Pretty mental.

Which artists do you look up to?
I remember hearing people like Joe Cocker, Fleetwood Mac and Elvis, my parents were big fans of them and they were the early seeds. My brother was more into Slipknot, and I still listen to them too, but it wasn't until I listened to Paolo Nutini that it really clicked. I've always loved raspy voices, and he sounds like music that was made back in the '60s. I missed his first album, but it was the second one (2009's Sunny Side Up) that really did it for me – soul music with a gritty voice, but for me still really pop. It made me realise that you could make music like that now and people would still listen to it, if it was good. Hearing him was a big turning point for me, and I also liked people like Jake Bugg – his first record, especially – and Ben Howard. Recently I've been getting more immersed in pop music and rap.

What's next?
I know up to March we're pretty much slammed with touring in America, and then my own headline UK and European dates. Then I'll be focusing on more writing and trying to finish the album, it'll be out hopefully by the end of the year, and if not, then early 2019. The main thing right now is to get the music out to people as much as I can by playing it to them live, though.

Lewis Capaldi plays the ABC, Glasgow, Sat 17 Feb. The BBC Sound of 2018 top five will be announced between Mon 8 and Fri 12 Jan on BBC Radio 1.