If there is a single cable channel that could be given credit for revolutionizing the television industry, that channel would probably be MTV. When Music Television began airing in 1981, it was entirely unique, and it helped to fuel unprecedented public enthusiasm for cable programming and drove the expansion of cable TV into all corners of the American market.
In its original incarnation, MTV was essentially a televised version of a radio station, with VJs ("video jockeys") who presented music videos in much the same way that DJs ("disc jockeys") presented popular songs on radio. The format popularized the music video concept and significantly changed not just the cable TV industry, but the recording industry as well.
The channel's focus on music remained through the 1980s, but in the 1990s, MTV began slowly branching out into other programming niches. "MTV News" segments began to establish the channel as an advocate of youth-oriented social issues, game shows like "Singled Out" echoed the resurgence of the genre on TV, and "The Real World" was one of the earliest examples of the reality-TV genre.
Since the turn of the century, MTV's music programming has been a minority of its schedule. The channel focuses instead on reality TV, animation, original scripted series and other youth-oriented programming.