A product of the arts-oriented Saint Ann's School, Diamond was born in New York City to a Jewish household. In 1979, Diamond co-founded the band The Young Aborigines. In 1981, Adam Yauch, aka MCA, a friend and follower of the band, became their bass player, and on the suggestion of their then-guitar player, John Berry, the band changed their name to the Beastie Boys. By 1983, Adam Horovitz (Ad-Rock) joined, and their sound began to shift away from punk to hip hop.