Lady Gaga is now in Los Angeles prior to her debut performance with Tony Bennett at the 57th Grammy Awards, but that doesn't stop her to keep working. During her off time Gaga was in the recording studio with Sir Paul McCartney and a crew of "killer" musicians in what appears to be some secret major project. 

Had a beautiful session with Sir Paul McCartney and friends. Working on one of his many secret projects! Killer musicians, vibe, and lots of laughs.

Una foto publicada por @ladygaga el 3 de Feb de 2015 a la(s) 5:57 PST

Always a good time with my buddy. I'll never forget when he called me last year to work and I hung up the phone cuz I thought it was a prank!

Una foto publicada por @ladygaga el 3 de Feb de 2015 a la(s) 6:00 PST