Behind the songwriter-producer’s recent hits, including the biggest smash of the year. Daniel Nigro vividly recalls the moment his obsession with pop music started. While in sixth grade, he heard Nirvana's “Smells Like Teen Spirit” for the first time; soon after, he and his friends made their own music video to the hit through an attraction at Long Island’s Adventureland. “Even making a fake music video, I was like, ‘Oh yeah, I want to be playing for people,” says Nigro. But after fronting the indie-rock act, As Tall As Lions, which disassembled in 2010, he had another realization: “I’m actually not that good at this, and also don’t really enjoy it.”