Beastie Boys were an American hip hop band from New York City, formed in 1981. For the majority of its career, the group consisted of three MCs and musicians Michael "Mike D" Diamond (vocals, drums), Adam "MCA" Yauch (vocals, bass) and Adam "Ad-Rock" Horovitz (vocals, guitar).

Originally formed as a four-piece hardcore punk band in 1981 by Diamond (vocals), John Berry (guitar), Yauch (bass) and Kate Schellenbach (drums), the band appeared on the compilation cassette New York Thrash, before recording their first EP Polly Wog Stew, in 1982. After achieving moderate local success with the 1983 experimental hip hop 12-inch "Cooky Puss", the group made their transition to hip hop in 1984 and released a string of successful singles. The Beastie Boys toured with Madonna in 1985 and a year later released their debut album Licensed to Ill. The group sold 22 million albums in the United States and 40 million albums worldwide, making them, according to Billboard, "the biggest-selling rap group" since 1991.