Michael Louis Diamond, famously known as Mike D, is an American rapper, musician, and a founding member of the pioneering hip-hop group Beastie Boys. Born in New York City, he formed the group in 1981 with Adam 'MCA' Yauch and Adam 'Ad-Rock' Horovitz, transitioning from hardcore punk to hip-hop. The Beastie Boys achieved massive commercial and critical success with albums like 'Licensed to Ill,' 'Paul's Boutique,' and 'Ill Communication,' becoming one of the best-selling rap groups of all time. Beyond his work with the Beastie Boys, Diamond has also been involved in producing, remixing, and interior design, cementing his legacy as a versatile and influential artist.