There has been some monster music studio sightings in the last few days.

First, Def Jam Exec Lenny S. posted a photo of heavyweights Jay-Z, Nas, Justin Timberlake, and Timbaland together in the lab with the caption: "JAY x JT x NAS x TIMBO Rat Pack shit. For some this is 'Work'… For us it's just Fun." We're not sure if this is a collaboration for the second installment of JT's The 20/20 Experience, due September 20, but whoever it's for, we know it will be legendary.

Secondly, after wrapping a GKMC tour stop in Detroit recently, Kendrick Lamar, ScHoolboy Q, Ab-Soul and Jay Rock was spotted in the studio with Eminem, Royce Da 5'9" and Mr. Porter. We know Em is working on a new album, so hopefully we will get this collaboration.

Check out the studio photos below:

Jay-Z, Nas, Justin Timberlake, Timbaland

Kendrick Lamar, ScHoolboy Q, Ab-Soul, Jay Rock, Eminem, Royce Da

Kendrick Lamar, ScHoolboy Q, Ab-Soul, Jay Rock, Eminem, Royce Da

Kendrick Lamar, ScHoolboy Q, Ab-Soul,Jay Rock, Eminem, Royce Da