Kanye West’s The Life of Pablo has a who’s who of collaborators, so when you get an opportunity to talk to a few of them (Charlie Heat, Desiigner and Havoc for starters) you’re bound to get some interesting stories.

The FADER recently spoke with Fonzworth Bentley to share an incredible and detailed breakdown of how Pablo’s first track “Ultralight Beam” came together. Bentley is officially credited as a co-producer with Rick Rubin, but it sounds like he had an important hand in the song’s shape and vision. He suggested adding tambourines, as well as adding the voices of Kelly Price and Kirk Franklin.

Quite possibly the coolest gem was Bentley revealed Poo Bear—the songwriter who helped write “What Do You Mean?”—and Justin Bieber were in the studio laying down something for “Ultralight Beam.” During this studio session in Los Angeles, Kanye wanted everyone to freestyle and catch a vibe. After ‘Ye and Chance freestyled, Bieber also did something acapella, but it ended up not making the final cut. You can read a portion of the interview below, and head over here to get the whole story.

I called Poo Bear, who's from College Park and wrote a lot of Justin Bieber's album. And he was with Justin at the time. I'm from Atlanta, Poo Bear is from Atlanta—so Poo Bear comes up and catches the vibe. Justin hops on the phone and is like, “Tell Yeezy whatever he needs I got it.” So Justin comes through and we vibed on that. And then Ye went right in. Ye was like, “Let's all catch a freestyle.” In his freestyle he said, "This is an ultralight beam." He sings that and was singing the melody. Then Chance catches the vibe. A lot of what ended up in his verse was from this freestyle—as far as his patterns and some of the words. There weren't that many words, more so vibes and patterns. Then Justin got on the mic and sang some a capella. It was free flow. It was creativity.