The British singer-songwriter, who occasionally mixes nimble melodies with hip-hop sensibilities, is riding the breakthrough of his debut album, "+," which has gone five-times platinum in his homeland and hit No. 5 on the Billboard 200 across the pond. His single, "The A Team," is nominated for the Grammy Award for Song of the Year as well as a pair of Brit Awards in the U.K., while its follow up, "Lego House," is building its own story.
On top of that, Sheeran co-wrote boy band One Direction's hit "Little Things," and he teamed with Taylor Swift to duet on "Everything Has Changed" for her "Red" album. Sheeran also will be Swift's opener when her Red Tour kicks off March 13 in Omaha, Neb.
Sheeran, 21, says he's surprised by the magnitude of his success. But not that he's having it.
"It's kind of happened very gradually; I've gone from strength to strength, and there's never been a point where it stalled," he explains. "When I started off, I was getting love for what I was doing - just not a massive amount of it. So, yeah, I though there was potential. I just didn't realize it would kind of get as big as it has."
And Sheeran is keenly aware that one hit, even a big one like "The A Team," does not guarantee a career.
"There's a danger of it having a sell-by date; everything could end tomorrow in this kind of musical climate," he acknowledges. "So I've just got to keep working as hard as I can and being nice to everyone and making music people want to listen to, I guess."
Sheeran started making music at home in Suffolk, England, northeast of London. After listening to a lot of Van Morrison music his parents played in the car during drives to London, Sheeran learned to play guitar and was at first playing electric heroics, "doing covers of, like, Eric Clapton and Guns N' Roses and very guitar-driven people." But when he was 11 he caught a show by Irish troubadour Damien Rice that proved pivotal.
"I saw him in a very, very small venue in Dublin, and that was the first time I'd seen anyone like that perform really, really up-close and personal," Sheeran recalls. "He just captured the whole audience for two hours and didn't let them go. It was an amazing experience, and I was like, 'Wow, maybe I should try writing songs' and kind of picked up an acoustic guitar and did that whole thing."
After that epiphany, Sheeran says he "never really had a Plan B for his life." He started writing songs in high school and released the first of his dozen EPs in 2005. He moved to London in 2008, when he was 17, working as a guitar tech for the duo Nizlopi before striking out on his own. He was such a driven live performer than in 2009 he played 312 shows. And his pop/hip-hop hybrid became enough of a crossover sensation that rapper Example took Sheeran on tour. Jamie Foxx, after seeing Sheeran perform at his Los Angeles club The Foxxhole, offered him free use of his Hollywood home and recording studio.
"I've always been a fan of different styles of music, but I found the main styles I was listening to were kind of hip-hop and acoustic singer-songwriter music, listening to people like Eminem and Jay-Z and to people like Damien Rice and David Gray," Sheeran says. So I guess the blend came from lots of influences from those genres."
Sheeran signed a major-label deal in early 2011 and played "The A Team" just four months later on the popular TV show "Later ... with Jools Holland." The song was written two years prior, when the 18-year-old Sheeran was volunteering at a homeless shelter.
"I wrote it about one of the women I met there," who was a crack addict, he notes. "It was kind of based on her story and her life and everything that happened to her. Being 18 I was kind of naive at the time. I didn't realize how dark some of the elements of London can be."
Not exactly slam-dunk hit material, is it? "No - especially in America," Sheeran agrees. "I never expected it to take off the way it has there. I remember going to radio in America and people being very skeptical about whether they could play it or not because of the subject matter, but it connected."
"The A Team" wound up hitting the Top 10 in 10 countries, and No. 1 in Britain.
The U.S. reception, meanwhile, is the source of great optimism for Sheeran and his camp.
"I feel like if everything keeps going the way it is, it's going to be bigger in American than it is anywhere else in the world," he explains. "The stage I'm at now in America, both livewise and record saleswise ... is far greater than it was in the rest of the world after having one single. I'm selling out, like, 6,000- 9,000-capacity rooms with one single, where in England I've only just reached that point with a five-times platinum (album).
"So, yeah, it's very interesting."
Sheeran's collaborations - including the 2012 EP "The Slumdon Bridge" with Alabama rapper Yelawolf - haven't hurt, either. The One Direction association came from meeting Harry Styles before there was even a group.
"When they got together, (Styles) said, 'Oh, we're looking for songs for our album, and I know that you write songs. If you could give us a song, that'd be great,' " Sheeran remembers. "So I gave them a tune for their first record which ended up going down quite well, and they asked for songs for their second record and I gave them two, and ('Little Things') hit No. 1 in the U.K."
Taylor Swift, meanwhile, identified herself as a fan by writing some of Sheeran's lyrics on her arm during a concert in Australia. Learning about it from one of his fans, Sheeran "put it out there that I really respect her and I'm a fan of Taylor's - not just her work but her ethics and that she writes her hits herself and she's probably the only woman in her position in the industry who writes 100 percent of her hits. It's a very cool thing."
Sheeran wound up meeting Swift's manager at one of his shows in Nashville, and the two connected to work on "Everything Has Changed" and two other songs that remain unreleased for now. "I hope they do something good with them," he says.
More headlining dates and then the Swift tour lay ahead for Sheeran, but that's not stopping him from homing in on his second album. Sheeran says he has "around 26 songs" already in hand, and he plans to write and record into the fall, with plans to release it in February 2014.
The record's definitely on its way," says Sheeran, who despite plenty of material between "+" and his many EPs is excited about adding to his catalog. "Y'know, most of the first record was written when I was 17, 18 at the time, and I'm 21 now. I've definitely evolved in the way I write songs and the way I perform, the whole mindspace. So it's just going to be a little more developed, I think."