Lady Gaga Joins Forces With Beyonce!

But can these two pop divas handle each other???

An insider reveals to Life & Style that Lady Gaga was working on Beyonce's latest music video in NYC a week ago - "Everything on the set was being kept very hush-hush, and security was extremely tight."

The song is "Video Phone" off Beyonce's most recent album and, even though Gaga doesn't appear to have any lyrics on the track, she "wears something wild. The fashion is sick and insane," the source adds.

We hope this music vid is (Sasha) Fierce!