The quartet popped in the studio, though it is unclear if they were all working on a group collaboration.
Kendrick Lamar, Pharrell Williams, Mac Miller and Busta Rhymes hit the studio together, though it is unclear if they are recording a collaborative track.
In a series of photos posted on BBCIceCream.com (via MissInfo.tv), the four are pictured hanging out in the lab. They are also joined by female singer Leah LaBelle, who is recording her Epic Records debut under Pharrell and Jermaine Dupri.
Check out flicks from the studio session below.