In 1994, South African media was liberalized and new musical styles arose. Prophets of Da City became known as a premier hip hop crew, though a South Africanized style of hip hop known as kwaito soon replaced actual hip hop groups. In kwaito, synthesizers and other electronic instruments are common, and slow jams adopted from Chicago house musicians like The Fingers, Tony Humphries and Robert Owen are also standard. Stars of kwaito include Trompies, Bongo Maffin and Boom Shaka.