Beck joins Paul McCartney onstage at PETA anniversary gala

Longtime PETA supporter Paul McCartney was on hand for the organization's 35th anniversary gala in Hollywood last night, and the Beatle took the stage with his band and a little help from his friends, namely six-time Grammy winner Beck. The 2014 Album of the Year honoree joined McCartney for renditions of "I've Just Seen a Face" and "Drive My Car" midway through a 20-song set rife with some of his most well-known hits. (Fan-shot video of the collaboration is above.)

Among the many classics performed by McCartney were "Got to Get You Into My Life," "Lady Madonna," "Let It Be" and "Hey Jude," as well as deep cuts like "Another Girl" from the Help! soundtrack and "Looking for Changes," an animal-rights anthem that first appeared on his 1993 solo album Off the Ground and which hadn't been played live in more than two decades. "I saw a cat with a machine in his brain," the song begins. "The man who fed him said / He didn't feel any pain / I'd like to see that man take out that machine / And stick it in his own brain / You know what I mean?"

Earlier in the week, McCartney and the Beatles donated the song "Can't Buy Me Love" to a new PETA PSA promoting animal adoption. The song, which included adopted dogs and cats, also featured an appearance from Baila Conmingo, a salsa troupe who became finalists on "America's Got Talent."

McCartney, 73, has been a vegetarian since 1975 and has lent his name to animal-rights causes over the years, including campaigns by the Humane Society of the United States and the World Society for the Protection of Animals. Together with his daughters Mary and Stella, he launched Meat-Free Monday, a not-for-profit campaign that seeks to raise awareness of the environmental impact caused by eating meat.

"Many years ago, I was fishing, and as I was reeling in the poor fish, I realized, 'I am killing him, all for the passing pleasure it brings me,'" he wrote in a 2008 PETA testimonial. "And something inside me clicked. I realized as I watched him fight for breath, that his life was as important to him as mine is to me."

The 35th anniversary gala also honored prominent PETA advocates, including Alicia Silverstone, RZA, Bill Maher, Jason Biggs, Fred Willard, James Cromwell, Jane Velez-Mitchell, Jillian Michaels, Kate del Castillo, Maggie Q, Marco Antonio Regil, Mary Matalin, Mike White, Noah Cyrus, Shaun Monson and Tommy Lee.