Looking at the liner notes to Taylor Swift's blockbuster album Lover, there's one name that stands out among the familiar roster of pop hitmakers -- Cautious Clay, the moody alt-R&B-pop artist credited as a songwriter on Swift’s track “London Boy.”

The Lover inclusion (Swift interpolates his stand-out 2017 track “Cold War”) is only the latest in a string of notable accomplishments and collaborations for the 26 year old, who also landed on the soundtrack for the third season of 13 Reasons Why with “Swim Home,” a collaboration with John Mayer. Earlier this year he released the EP Table of Context and Mayer recently dropped another Clay collab, the shimmering "Carry Me Away." Clay plays Atlanta’s Afropunk festival (Oct. 12-13) before detouring to Europe and winding back in the States for a one-month run that begins in Nashville on Nov. 12.

Clay spoke with Billboard from his co-op in Brooklyn about crafting his unique sound, connecting with Mayer through DM and how he became a part of Swift’s creative universe. “I did not at all foresee it happening. But at the same time, all of this stuff that’s happened to me over the last two years I can’t even say I could have predicted.”

In 2015 you remixed the Billie Eilish song “Ocean Eyes” while you were still working in real estate.You were both brewing and broke out around the same time. What goes through your mind when you think of that passage of time?

Yeah, it’s really insane. I’m so proud of Billie. She’s seriously the craziest rock star I’ve ever seen in my life, it’s insane. Her and her brother are both really good people. We were both just doing our own thing and so much of that was just born out of our love for making weird music. Not weird... just different, I guess. I definitely feel very fortunate and excited to be able to still be doing it.

You and Billie are unapologetically yourselves and you’re not trying to sound like anyone else. I’m wondering where that comes from? Could it be crafting your career through the internet?

(When I first started) I was super inspired by a lot of stuff happening on SoundCloud, a lot of beat producers and remixers, because that’s what I was listening to at the time. A lot of those artists are still doing cool stuff too, but we were all just sort of trying to push the limits of the sonics and not even just the songwriting, but how it sounded. That even goes for the ambition I had when I did that Billie Eilish remix. In all honesty I think it’s interesting because the production elements of that song were very minimal where I thought, “Oh man, maybe I can do more with it.” At the time, I was thinking more in the production mindset than songwriting, but I quickly learned how to write songs. I’ve always had a strong sense of words, but I never really merged those two worlds together. That’s how Cautious Clay became what it is now.

Speaking of the Billie remix and the fact that one of your big breaks was when a label from South Korea reached out to you through SoundCloud, that kind of leads us to this continuing collaboration with John Mayer. I understand he reached out to you through Instagram?

Yeah, it was basically a situation where he started following me and I noticed it and thought it was crazy. I didn’t even know why he was following me. So I hit him up and he said he liked what I was doing. I said, “Cool man, if you ever want to work, let’s work.” He was inclined to do that, so we set up a time from there and made “Swim Home” the first day we met.

I think there’s something to be said about a collaboration starting like that, as opposed to a manager or A&R saying, “Hey, I’m going to put you in a room with John Mayer.” What's the dynamic when you’re creating together? Does he have a guitar out?

With “Swim Home” he had a guitar and he uses ProTools into an MPC and that’s how he creates his ideas. He had that all set up, and I was singing into a microphone with my flute out. We were just riffing on ideas and eventually he came up with this really cool guitar lick and I was like, “Oh, this is nice.” He had a little change, which ended up being in the pre-chorus of the song. We engineered the song really organically.

I hear “Carry Me Away" came together very quickly.

This is literally fresh news. I replied to something on his Instagram story and I asked to hear the song he was working on. He sent it to me and asked if I had any suggestions or ideas and (he told me to) try some of them out. I started working on it that night at 2am and I probably finished it around 5 in the morning. What he sent me was basically a finished product, but I added this melody and background vocal at the end of the song. It’s the last thing you hear and it sounds like a guitar, but it’s my voice. I sang really, really high.

When Lover came out, Taylor Swift credited you as a co-writer on her song “London Boy.” How did this come about and did you ever think for a moment you’d be a part of the Taylor Swift universe?

Absolutely not. I did not at all foresee it happening. But at the same time, all of this stuff that’s happened to me over the last two years I can’t even say I could have predicted. The funny (beginning) to this whole scenario is that one of the first times I ever hung out with John Mayer, we were at this wine bar in Los Angeles and we were both walking out and we see Jack Antonoff. Basically, Jack and John know each other and I introduced myself but I don’t even know if he knew who I was and he said, “Cool, nice to meet you” and we all went on our way. Nine months later this past July, I’m in Norway and it’s 5am and I get a call from my manager saying that Taylor Swift wants to interpolate “Cold War” on my “London Boy” track. I didn’t get to hear the song at all or know anything about it but had to approve over the phone whether or not we’d be okay with the splits in 24 hours. We eventually made an agreement and it came together. It was completely out of left field.

So you couldn’t listen to it beforehand?

No, they didn’t send it to me and I didn’t know what it sounded like. I think her team is just very secretive about what they allow people to hear. For better or for worse, I went with my gut and from my perspective, I was thinking if it’s just an interpolation (then it’d be fine). I think she really made it her own, which is really cool. I’ve also spent a lot of time in London (but I guess) it’s about her boyfriend. It is what it is. I can hear the reference to “Cold War.” I think she has some good songs and is a good artist and is super genuine to what she’s doing.