Grandmaster Flash and the Origins of Breaking

Here's the story that is often told about the origins of hip hop DJing, mixing and cutting:

Once upon a time, Grandmaster Flash, whose real name was Joseph Saddler, started noticing that there were certain points in the music when people were most likely to hit the dance floor. By paying attention to when things really went off on the dance floor he discovered that the break was the most engaging part of the music for most people. By isolating the breaks in songs and playing them in a short loop (this is called the backspin theory or the quick-mix theory) he was able to present only the most engaging parts of music to his audience. And thus, a new style was born: the birth of breaking. Punch phrasing (or clock theory) is also attributed to Grandmaster Flash and involves isolated segments- most often horn hits- and replaying them over the sustained beats. While not attributed to creating scratching, Grandmaster Flash is generally considered to have perfected the art and brought it to the masses.