Mr. Pop’s “Nightclubbing,” a song on “The Idiot” that reflected postconcert club excursions across Europe with Mr. Bowie, was recorded with a cheap synthesizer and an early drum machine, the only equipment available after a recording session had been packed up. “He said, ‘I can’t put out a record with that,’” Mr. Pop recalled. “I said, ‘But I can.’ And he smiled, and he realized this was a playground for him. I always tried to encourage his worst impulses in those directions. I was a fan.”

When Mr. Bowie moved to Berlin, Mr. Pop occupied a room in Mr. Bowie’s apartment there “over the auto parts store,” he said. The title song for Mr. Pop’s next album, “Lust for Life,” germinated in that apartment.

Mr. Pop and Mr. Bowie, seated on the floor — they had decided chairs were not natural — were waiting for the Armed Forces Network telecast of “Starsky & Hutch.” The network started shows with a call signal that, Mr. Pop said, went “beep beep beep, beep beep beep beep, beep beep beep,” the rhythm, which is also like a Motown beat, that was the foundation for “Lust for Life.” Mr. Pop recalled, “He wrote the [chord] progression on ukulele, and he said, ‘Call it “Lust for Life,” write something up.’”

Mr. Bowie “saw me sometimes, when he wanted to voice it that way, as a modern Beat or a modern Dostoyevsky character or a modern van Gogh,” Mr. Pop said. “But he also knew I’m a hick from the sticks at heart.”

By contrast, Mr. Bowie was “worldly,” Mr. Pop said. “I learned things that I still use today. I met the Beatles and the Stones, and this one and that one, and this actress and this actor and all these powerful people through him. And I watched. And every once in a while, now at least, I’m a little less rustic when I have to deal with those people.”

Mr. Bowie made a point of visiting Mr. Pop’s parents in Detroit, where they were living in a trailer. “He came to my parents’ trailer, and the neighbors were so frightened of the car and the bodyguard they called the police,” Mr. Pop said. “My father’s a very wonderful man, and he said, ‘Thank you for what you’re doing for my son.’ I thought: Shut up, Dad. You’re making me look uncool.”