Musician and former Beatles member Sir Paul McCartney joined tens of thousands of participants for New York City’s March for Our Lives on Saturday. The march, held in favor of gun control, was part of a web of rallies that took place across the country, including in Boston.

“One of my best friends was killed in gun violence right around here, so it’s important to me,” McCartney told CNN.

McCartney’s bandmate, John Lennon, was murdered in New York City in 1980.

When the CNN reporter asked what McCartney hoped could be accomplished, the musician stepped back to reveal his shirt, which read, “We can end gun violence.”

"One of my best friends was killed in gun violence right around here, so it's important to me," says Paul McCartney, remembering his Beatles bandmate John Lennon at the March for Our Lives in New York City https://t.co/u4aBKWC1Jb pic.twitter.com/8Jnjn8A3xH — CNN (@CNN) March 24, 2018