Dean Bein, the founder of True Panther Sounds, Mr. Marshall’s label, wrote in an email that upon meeting the singer, at 15, “I knew he was special. Even then, he didn’t do anything for the look or for attention. His moves are always decisive.” Mr. Bein recalled Mr. Marshall turning down a “super prominent magazine cover” early on “because he felt he hadn’t earned it yet,” and balking similarly at “some very notable collaborations because he couldn’t see how the artists’ sounds would work with his.”

Mr. Marshall was more blunt. “I remember even getting hit up by Kanye to go to the studio. Anyone else in my shoes would’ve done it,” he said. “I couldn’t be bothered.” It wasn’t out of a sense of superiority, he stressed, but because of the pressure to create on call.

“I like the physicality of living with someone, sleeping next to them, eating with them. And eventually we might make a tune,” Mr. Marshall said. “I’ve turned down so many opportunities where I could maybe be rich right now.” He stopped himself with a laugh and an expletive. “Ugh, why didn’t I do it?”