Without warning, Kendrick Lamar surprisingly released his sixth album on Friday, November 22, GNX. Featuring vocals from SZA and production from “Not Like Us” producer Mustard, alongside the likes of Sounwave and Jack Antonoff (another shocker), the 12-track album clocks in at just under 45 minutes.

‘You know what’s crazy? It was a surprise to me, just like it was a surprise to everyone,” Mustard said. “I thought it might happen at the top of the year, maybe around the Super Bowl or whatever. I’m at the gym today working out and I see him post a snippet of a song and I’m like, ‘Oh shit, this shit is probably coming next week.’ I think of Thanksgiving when everyone is in the house together. Ten minutes later the album is out.”

“TV Off” – one of the songs Mustard co-produced (along with Sean Momberger, Sounwave, Antonoff and Kamasi Washington) emerged as an early GNX notable, in part because of its close relationship to Lamar’s knockout hit “Not Like Us,” which Mustard says was “absolutely intentional.” And just as the album arrived without warning, Mustard had yet to hear the finished version of the song until today.

“What was I thinking?” he says, his energy palpable. “I was losing it. I mean, I already knew I was doing the beats, you know? But Kendrick is the best rapper, bro. Of all times. I think he’s one of the best.”

Mustard says he made “TV Off” around the same time as “Not Like Us,” but clarifies that the two halves of “TV” were made at different times and to two different beats. “That first half was definitely in the same vein where I made things like ‘Not Like Us,’” he says, “and the second half was a beat I did for this other theatrical album I’m trying to make. And I was like, “Man, let me see if Kendrick would like this.” I sent it to him and he said, ‘This is crazy.’

Even crazier? The few-second transition between the two sections in which Lamar enthusiastically shouts “Mustaaaaaaaaaaard.” As Mustard himself says: ‘That was elite. So fire. Is that a new tag? I can’t wait to perform that song and just hear people say that because everyone’s going to say that like crazy.

As for “Hey Now” (another of his co-produced songs), Mustard made that beat himself 3-4 years ago before Sounwave and Antonoff added to it. “I just knew that if I got the right person to do it, it would be perfect. I sent it to (Kendrick) and he got it right away and said, “Okay, I know what to do.”

“I have this thing where I try to send (Kendrick) something every day,” he continues. “I always wonder what’s next. You know, this morning I texted like, “What do you need from me?” Whatever it is, I’m in and ready to just keep my head down and keep working.”