Rick Rubin took up residency on Genius yesterday, Feb. 2, and the results are amazing. The super producer broke down the back stories of several famous songs, most notably tracks from Kanye West, Jay-Z and Johnny Cash.

Let's start with Kanye's "Only One." Rubin was in St. Barths two days before the single came out on New Year's Day. Kanye said, "I'm thinking about putting out 'Only One' tomorrow at midnight." Rubin responded, "Should we mix it?" Kanye: "It hasn't really changed -- it's pretty much what it was." Rubin had not heard it in almost two months, so he requested the file and concluded that they could make it sound better.

Rubin got in contact with three different engineers to try their hand at a new mix.

"This is the day before New Year's Eve, and we're all finding studio time, getting the files," Rubin said, via Pitchfork. "Then they all start sending me mixes. I thought one was better than the others, and Kanye agreed. One guy mastered it, because it was due, and they turned it in. I had another guy master it, and it was better, but it was already too late. I think it switched the following morning. It was in real time! Like as soon as it was better, we had to switch it.

"That's how it works in Kanye world. It used to really give me anxiety, but now I just know that's what it is. That's how he likes to work."

Then there was the story about "99 Problems." You know that famous shout-out Jay gives Rubin? "You're crazy for this one, Rick!" Well, Rubin originally wanted to scrub it from the song.

"When we were finished, when we were putting it together, I was taking that ad-lib out, and he was like 'No, no. That stays in,'" Rubin recounted. "I was like, 'Really?' I come from an era of hip-hop where we didn't do shoutouts. A pre-shoutout era."

To the non-hip-hop crowd, Rubin is perhaps best-known for his work with Johnny Cash, as the two collaborated on "Hurt" together.

"What I came to realize about that whole Johnny Cash experience was that he was a great storyteller," Rubin said. "The song didn't matter -- all that mattered were the words. All that mattered was if the character of Johnny Cash -- the mythical Johnny Cash, the man in black -- would say those words. If that's what you would want to hear him talking about, then that would be a good song to do."