In an era of e-mail collaborations, Kendrick Lamar's preference to hole up in the studio with a group of collaborators and improvise new music in real-time is becoming an increasingly rare occurrence. Top Dawg Entertainment in-house producer Sounwave has been on record saying: "The whole process of this album [To Pimp A Butterfly] is you literally had to be in the studio with us to get the sound we're trying to portray."

This week, jazz musician Kamasi Washington (who was brought in by Terrace Martin to add string arrangements to the record) sat down with comedian Marc Maron on his popular WTF with Marc Maron podcast and told stories from the sessions.

"The amazing thing that I was struck with first was that he was so hands on," Washington said. "Day one, he was like, ‘Okay Kamasi, write some stuff to this.’ I’m like, ‘Okay, do you want to give me the files and I’ll go home and come back?’ He’s like, ‘No, you’ve got to write this here. You don’t get to leave with anything.’"

"So I’m just sitting there listening to the music, and I have a little piano set up, and Kendrick’s just sitting there on the couch watching,” he laughed. “But wasn’t a vibe of like, ‘Let me make sure you don’t do anything I don’t want you to do.’ It was more like, ‘I’m just curious to see how this process works.’"

After explaining how different the experience was compared to the increasingly popular e-mail sessions, Washington told a story about one moment in particular that impressed him about Lamar.

"I would see him do superhuman stuff," Washington said. "One day, Terrace [Martin] brought in a new beat, and I saw Kendrick just create a whole song while he was hearing it for the first time. And it felt like a complete song. I was like, did you just create that right now while I was sitting here as you were listening to it for the first time? Wow. That’s amazing.”

Listen to the full podcast here. The conversation about the To Pimp A Butterfly sessions begins at the 54:00 mark.