Famed producer Rick Rubin is now on Genius, making his way through a variety of material and adding annotations to songs of artists he’s previously worked with, among others. Rubin interjects stories, perspective, or unknown tidbits about some of his most iconic musical partners including Kanye West, Red Hot Chili Peppers, Metallica, Jay Z, Beastie Boys, Johnny Cash and many more. Read the full, continuing list here and check out some highlights below.

Interestingly enough, Jay Z requested a “Beastie Boys vibe” which led to his biggest hit, “99 Problems.”

Jay came into my studio every day for like a week, I kept trying things that I thought would sound like a Jay record, and after like three or four days he said, “I want to do something more like one of your old records, Beastie Boys-style.” Originally that’s not what I was thinking for him, but he requested that vibe, and we just started working on some tracks.

Musically, there were a couple of different ideas that [engineer] Jason [Lader] and I were working on independently that we played back together, and the way the beats overlapped was really interesting. It wasn’t planned out, it was more experimenting.

There was a part where it really sounded crazy and the beats were fighting each other. Jason was operating the Pro-Tools, and I’m saying “Move to the left, move to the right, try this beat, add this, do this,” and then he makes it do it. There’s nothing live on the track.

It’s a combination of three samples — “The Big Beat” by Billy Squier, “Long Red” by Mountain, and “Get Me Back On Time” by Wilson Pickett — and two programmed beats coming in and out.

Adam Yauch hated Slayer despite Kerry King adding his guitar to “No Sleep Til Brooklyn.” Rubin has worked on every Slayer record since 1986’s Reign in Blood.

Kerry King did the solo right here, much to the dismay of Adam Yauch. He hated Slayer. He didn’t like metal.

If Johnny Cash were alive today, Rubin would love to hear him have a go at Hozier’s “Take Me to Church.”

It’s a classic, great song. Just the way it makes me feel. It’s a guitar-based song that is acceptable in today’s world. That’s interesting. I love the dynamics in it. The lyrics are dark, but spiritual.

It’s one of the songs where if Johnny was alive, we might try that one. It’s a weighty song.

He loves Beck’s Morning Phase.

I absolutely love Morning Phase. Probably my favorite album of 2014. It’s definitely his best. I like it a thousand times better than Sea Change.

…And Vampire Weekend’s Modern Vampires of the City.

An album gets me really excited is Modern Vampires of The City. I love it. I love it. What I like about it is that it sounds completely modern and it sounds completely traditional. It could be a Paul Simon record, but it sounds really modern. And no one else who’s doing modern has that much tradition in it. And that combination really speaks to me.

Here’s a great story about how Johnny Cash’s version of “Hurt” came to be and why he selected the Trent Reznor-penned tune to send him.

For all the records we made together, he would play me songs and I would play him songs until we got to the point where we both liked the songs. There were always hundreds of songs in play, not necessarily recorded but discussed.

You can usually tell which ones I brought to the table. “Rusty Cage” was mine, “Hurt” was mine. He wouldn’t have heard those. Something like an old Jimmmie Rodgers song, chances are he brought it.

There are some exceptions. He brought in a Sting song, a modern Sting song, “I Hung my Head” which is really good. He brought in a Springsteen song, although I don’t know if we ever put it out. He brought in some modern stuff.

There were a lot of songs that he needed to be convincing about. Eventually, he trusted me enough that if I felt strongly about something, he’d do it. I would send him compilations of CDs of songs to listen to, and I remember that on several compilations in a row, “Hurt” was the first song. There’s just something about it. I imagined him saying those words being very powerful.

What I came to realize about that whole Johnny Cash experience was that he was a great storyteller. 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.

So it was never about like melody, it was just about if the lyrics were right.

Damien Rice worked with Rubin on his 2014 LP My Favourite Faded Fantasy, his first in eight years and first with an outside producer. Here’s Rubin recounting his love for Rice’s songwriting and the process of recording with the prolific songwriter.

Damien’s words kill me. They’re unbelievable. Just one after another. He surprises me.

When he did “My Favorite Faded Fantasy,” he hadn’t made a record in eight years He made one album that was great, called O, and then another one called 9 that’s not very good. And then he disappeared, until now.

I would try to help him finish or just help him get out of his own way. Sometimes I’d say “I don’t think this line is good enough.” But, in this case, he wrote a lot of things that were really good and he just never felt confident enough about them, so it was more about empowering him.