Mos Def is an American rapper. He started his hip-hop career in 1994 with the group Urban Thermo Dynamics (UTD). He next worked with the artists Da Bush Babees and De La Soul. In 1998, he collaborated with Talib Kweli and released the album Mos Def & Talib Kweli Are Black Star. The following year, he pursued a solo career with the release of the album Black on Both Sides. In the 2000s, his follow-up albums The New Danger and True Magic came out. Def is also an actor, first appearing in the 1997 film Ghosts. In 2004, he portrayed Vivien Thomas in the TV movie Something the Lord Made, which earned him Golden Globe and Emmy nominations. He also had a recurring role in the TV series Dexter.