American rock there was a Garage rock/post-punk revival. The development of digital technology led to the development of new forms of digital electronic rock. The foundations of American rock music are in rock and roll, which originated in the United States in the late 1940s and early 1950s. Its immediate origins lay in a mixing together of various black musical genres of the time, including rhythm and blues and gospel music; in addition to country and western. In 1951, Cleveland, Ohio disc jockey Alan Freed began playing rhythm and blues music for a multi-racial audience, and is credited with first using the
Canadian Disc Jockey Association professional values and high standards that members are expected to follow. Individuals can apply for CDJA membership only after they have submitted a signed acknowledgement that they will conform to and operate within the code. The CDJA has 11 chapters across Canada. Canadian Disc Jockey Association The Canadian Disc Jockey Association (CDJA) is a not-for-profit trade association for disc jockeys across Canada. The CDJA was formed in 1976 and incorporated in 1978 to serve not only the disc jockey trade but the consumer, as well. It is a self-regulating association and operates under a national constitution and code of ethics.