In a recent interview with Jimmy Fallon, The Beastie Boys promoted their brand new memoir, which features historic moments in their careers and crazy stories about some of the most popular musicians of all time. The group’s influence is major in the realm of hip hop, shaping the way rappers rap and having the crossover appeal to become household names. Jimmy Fallon just so happened to be a major fan of the group. He invited Mike “Mike D” Diamond and Adam “Ad-Rock” Horowitz and they talked about a funny story about the late Adam Yauch, aka “MCA.”

Ad-Rock mentioned how one of MCA’s goals was to perform “Walk This Way” with Aerosmith and Run-DMC and, although not as expected, he ended up making it a reality. According to the group, MCA crashed an Aerosmith concert to play bass out of nowhere, leaving Joe Perry and many startled in the process. “So the song starts, people go crazy and then Yauch runs out with this bass,” says Ad-Rock. “You just look at the Aerosmith guys and they’re like, ‘Who is this guy?’ And then all of a sudden he goes up to Joe Perry and is trying to go back-to-back with him, like a rock guitar player. And Joe Perry was like, you could see him very uncomfortable and Yauch was chasing him around, running around backwards trying to play guitar.”

Not many can say they’ve crashed an Aerosmith concert and went on to create ‘License to Ill.”

Rest in Peace, MCA.