DJ Mathematics Part 1: Scratch History
1973: Kool Herc decides to DJ a party for his sister. He brings in two turntables, and switches from record to record without any pauses.
1974: DJ Pete Jones introduces a switch so he can control which of two records he is listening to on his head phones, and match the beats between them. Grandmaster Flash does the same but adds sampling techniques.
The mathematics of beat matching has roots in African tradition
It can also be seen in Afro-Caribbean music traditions
1977: Grand Wizard Theodore --at age 13! -- invents the scratch. This happened by accident -- he was just playing with a record while his mom was asking him to turn down the music, and he decided that he liked the sound imposed on the other record that was playing.
Some contemporary examples:
Oscillation of fader: chanfade.wmv
Serato Scratch Live
DJ Mathematics Part 2: Patterns in time
1) Fader time series waveforms
about other waveforms?
2) Turntable time series waveforms
But again, we have to think about other waveforms!