Eminem, "Berzerk" (2013)
That was a case where Eminem said, "Let's make one of those old records that we grew up on." We recorded it around a sample he made of someone on the news saying "go berserk." We built the beat first, and he wrote to the beat, all starting with that little clip of "go berserk." [Laughs] That was his inspiration. Then we programmed it on an 808 drum machine and used [Billy Squier's] "The Stroke" sample liberally. I played guitar, and we programmed everything else. It was a good one.
It was another one where he did the vocals by himself with no one watching in the room. Once he raps to a beat, you can't change anything. It's almost like all the drops, all the moves in the song have to happen before he writes to it because he writes into the music in a way that makes it hard to change anything after he raps. He uses his voice as another instrument that plays off of all the different rhythms going on in the track.
He's a real, unbelievable student of hip-hop. He's maybe the most obsessive artist I've ever worked with in terms of someone who just full-time is writing rhymes. It's what he does.