If MTV had come along in say 1975 or 76, how do you think it would have affected music around that time? I can already see many rock acts losing popularity, since the songs sounded good on radio, but looking at them playing was kind of dull (their concerts did well, but concerts are pretty much a big party anyway). I wonder how punk would be affected as well (it was a visual medium in some ways, but the violence may have scared off mtv).