right now, all around us, and so compelling you never miss the fact there is no melody is a music that is all beat, strong beat, and talk. it's rap music. rap music began in harlem in the south bronx on playgrounds like this one where people would gather to recite their own lyrics, their raps over the instrumental section. >> the brakes was curtis blow's biggest hit. selling 680,000 copies last year and hitting the top of the rhythm and blues sales charts. >> as a young kid running around with a local dj crew, i watched the transition from all the disco music we used to play at all the block parties to slowly but surely hip-hop taking over. >> the music underneath rapping is called scratching and it is a process of using two turntables