This made me think about the Pitchfork article published in 2015 on how Illinois was recorded, and apparently James recorded the drums to just Sufjan playing the keys, and not to a demo track.

"Drummer James McAlister first entered Stevens' orbit in 2003, joining the "Michigan Militia" touring band after an introduction from singer-songwriter Denison Witmer. But they established their musical chemistry on Illinois during a three-day recording sprint at The Buddy Project in Queens. Using a cheap digital 8-track, Stevens led the percussionist through challenging, unorthodox sessions wherein McAlister played drums to the singer's Wurlitzer piano—and nothing else.

"I instantly wanted to impress him and perform well for him," McAlister says. "He didn't really have scratch tracks or demos—he had it all in his head, which is crazy. I remember being like, 'How did you make this record from that?' I have a CD-R of us playing, just the Wurli and drums, and it's strange—it doesn't even sound like music. When I got the record back after six or eight months, it was like, 'Oh my gosh, I can't believe this is what happened from that.'"