Grandmaster

Joseph Robert Saddler (born January 1, 1958), known professionally as Grandmaster Flash, is a Barbadian-American DJ. He is regarded as one of the pioneers of hip hop DJing and is associated with the development of the "Quick Mix Theory", a technique that uses duplicate copies of vinyl records to extend drum breaks. The approach contributed to the development of techniques such as cutting, scratching, and beat juggling, and is also associated with the invention of the slipmat.