A source (not 50 Cent) tells the New York Daily News that Solange Knowles' infamous elevator attack on brother-in-law Jay Z happened after Jay made plans to head to Rihanna's Met Ball after-party without bringing Beyoncé.

One of the many unanswered questions about the elevator dustup between Solange Knowles and Jay Z at the Met Gala is why Beyoncé stood calmly by while her sister attacked her husband. Is Bey taking anyone's side, here?

The most disappointing thing about Beyoncé's sister losing it at Jay Z in an elevator is the lack of sound on the security tape, which makes it difficult to figure out what the fight was all about. Fortunately, it's 2014, so we have access to technology that can solve this problem: Namely, 50 Cent's Instagram account.

Here's the full video of Solange attacking Jay Z in an elevator, via TMZ. Shortly after the first video cuts off, Solange continues to talk—yell?—at Jay Z. Several seconds later, she tries again to hit him and is pulled away. Half a minute or so passes, and she lunges at him again, walloping him with her purse, which…