known by the stage names Mos Def (pron.: /ˌmoʊsˈdɛf/) and Yasiin Bey (pron.: /jæˈsiːnˈbeɪ/). He started his hip hop career in a group called Urban Thermo Dynamics, after which he appeared on albums by Da Bush Babees and De La Soul. With Talib Kweli, he formed the duo Black Star, which released the album Black Star in 1998. He was a major force in late 1990s underground hip hop while with Rawkus Records. As a solo artist he has released the albums Black on Both Sides in 1999, The New Danger in 2004, True Magic in 2006, and The Ecstatic in 2009. Editors of About.com ranked him number 24 on their list of the Top 50 MCs of Our Time (1987–2007). In 2012, The Source ranked him No. 23 on their list of the Top 50 Lyricists of All Time. Since the early 2000s, Mos Def's screen work has established him as one of only a handful of rappers who has garnered critical acclaim for his acting work. He is well known for his portrayal of Brother Sam in the American drama series Dexter. Mos Def has also been active in several social and political causes. Mos Def was born Dante Terrell Smith in Brooklyn, New York City, the son of Sheron Smith and Abdul Rahman. He was raised by his mother in Brooklyn; his father lived in New Jersey. While his father was initially a member of the Nation of Islam and later an active member in the community of Imam Warith Deen Mohammed, who merged into mainstream Islam from the Nation, Mos Def was not exposed to Islam until the age of 13. At 19, he took his shahada, the Muslim declaration of faith. He is friends with Ali Shaheed Muhammad and Q-Tip of A Tribe Called Quest.