The Billboard Cover Story: 2016 Predictions -- Charlie Puth Will Lay Siege to the Hot 100

Just over a year ago, Charlie Puth was a Berklee College of Music grad living at home with his parents in New Jersey. Now, at 24, he's one of the world's fastest-rising pop singer-­songwriters, with a gated house in the Hollywood Hills, Grammy and Golden Globe nominations and a hit -- Wiz Khalifa's "See You Again" -- that spent 12 weeks at No. 1 on the Billboard Hot 100 in 2015. "It has all happened stupid fast," he says with a chuckle. Today Puth is in New York after a late night with his new buddy Selena Gomez, cutting a song for his debut album, Nine Track Mind, out Jan. 29. "It's called 'We Don't Talk Anymore,' " says Puth, sitting in his hotel's restaurant. "Everyone knows what Selena has gone through, so she inspired it in a way."

Puth moved to Los Angeles to pursue songwriting in September 2014, having scored a publishing deal on the back of some popular YouTube videos (they also got him on Ellen). His first day in town, his publishing company set him up with a session that resulted in his current Hot 100 hit "Marvin Gaye," featuring Meghan Trainor. The next day, he met with the producer-DJ Frank E, who wasn't entirely delighted to be saddled with the new kid. But within 10 minutes, the pair had come up with most of "See You Again." With Khalifa onboard, the song was a perfect fit for the ­climactic scene in Furious 7 -- the studio sent out the song to everyone from Chris Brown to Jason Derulo but Puth's demo vocal worked best. "They all nailed it," Puth says. "But even Wiz was like, 'I like this kid's voice -- he sounds the realest.'"

Since then, he has performed on everything from The Tonight Show Starring Jimmy Fallon to Saturday Night Live with Khalifa. Puth doesn't smoke weed, to preserve his falsetto, so at one rehearsal the MC brought him a special gift. "He was like, 'Fool, put this in your tea!' " says Puth. "I was like, 'Why do I feel relaxed all of a sudden?' It was liquid THC!" Puth had his own major TV moment in November, when he and Trainor -- definitely just friends -- made out during their "Marvin Gaye" performance at the American Music Awards. "There are 19 performers there. What were we going to do to stand out?" he explains.

On Nine Track Mind -- which features a ­songwriting assist from his hero Max Martin on "Then There's You" -- Puth spikes his hooky sound with elements from his conservatory training. And he has been ­thinking about his first solo tour, launching this year, and navigating fame. "I went on a promotional tour all over the world and I saw all these beautiful girls -- I didn't kiss any," he says. "I didn't have time!" After a beat, he adds, "Well, I kissed some. But you know what I mean."