ARTICLE AD BOX
By Kirsty Grant
Newsbeat reporter
Sam Tompkins was in his "local boozer" in Brighton, a few pink gins down, when he got a FaceTime from his "hero", Justin Bieber.
"My mates just couldn't believe it," the singer-songwriter says.
"It was the weirdest day of my life. I was like: 'This cannot be happening at the Waggon and Horses pub.'"
Justin had followed Sam on Instagram a few days earlier, DM'd him to say he liked his music, and shared Sam's songs with his 206 million followers.
"I feel like I skipped a lot of steps when when I found out that he liked my music," Sam, 24, tells Newsbeat.
"I was like: 'Surely there's a couple of people that I've got to meet before I meet you?'."
On FaceTime Justin invited Sam to Los Angeles to work on some songs together.
Sam flew out there and spent a whole day with his new friend, going for lunch and working on new music.
"I couldn't have possibly asked for a better day with someone that I've looked up to my whole life.
"It just shows that anything is possible, especially with social media. You can really do anything and reach anyone."
Sam's career started at the age of 16, when he busked on the streets of Brighton for pocket money.
"I went to a skate shop in Brighton and I saw this hat and I couldn't afford it," he said.
"One of my mates suggested that I went and busked for it, because they knew I could sing."
He did - and he made the money to buy the hat "very quickly".
Sam started busking every weekend, and it wasn't long before he started doing gigs too. But wasn't always easy money.
He remembers once being booed off stage by people he'd grown up with in his hometown of Eastbourne, where he was opening as support act.
"It was brutal," he says.
"I came off and I remember that it was sort of a make or break situation for me."
Since then Sam's released EPs and singles which have brought in millions of streams by listeners, and gone on sold-out tours.
With big plans for new music and tours in 2022, Sam's not got plans to go back on the streets of Brighton much.
"It's important to know that people make a living off busking," he says.
"I don't want anyone to feel like I'm taking food away from their mouths, so I wouldn't do it too often. But I do it every now and then for fun."
He says his success in music has surprised him.
"It doesn't make any sense," he said. "And it's all happened very quickly. I feel very grateful.
"I've sort of exceeded any expectation I ever had of myself."