You've already seen the videos, but here's the incredible story behind them.
On Monday's "Tonight Show," Jimmy Fallon recapped the party after the "Saturday Night Live" 40th-anniversary special, and it was ridiculous. In addition to singing with Paul McCartney and Taylor Swift, Fallon recalled the star-studded lineup of celebs who also took the stage, including Miley Cyrus, Ariana Grande, Michael Bolton, Bill Murray and Elvis Costello. The story gets even wilder when Fallon dares Prince to come on stage, which involved the crowd parting, purple smoke and the singer flying with jetpacks on his knees (somehow that's actually believable).
Fallon called it "one of the best nights" of his entire life; and even though you weren't there, don't be surprised if it cracks your top ten, too.
"The Tonight Show Starring Jimmy Fallon" airs weeknights at 11:35 p.m. ET on NBC.