Ever stop and wonder just how DJs can take an ordinary vinyl record, scratch it up and produce a congruent piece of music? Just what are they doing with those fast fingers? A new visualization system has been developed to do just that. Created by Jessie Kriss, Visual Scratch syncs a computer with a turntable to produce a real time graphic depicting exactly what’s going on. A great educational tool and presumably also pretty useful for even a seasoned turntablist.
How exactly does it work?
We capture turntable velocity using Ms. Pinky and fader position using an Ecler Nuo 4. The scratching sound is generated in Max/MSP. Then we scale the control data (turntable and fader) to ±1.0, the range of digital audio signals. The control data is saved to one audio file, and scratch audio to another.
With the two sound files as input, the graphics are generated in Processing, using the incredibly helpful Ess, PDF and MovieMaker libraries. The y-axis position reflects the velocity of the turntable, color is based on the frequency content of the scratch audio, and the thickness of the line is based on the volume.
If all of that is still going over your head, check out the demonstrations on their site. They walk you through various scratches such as the Flare, the Chirp, Forwards, and the Transformer - complete with explanations, the history of the scratch, and of course, a visual description. This video also does a pretty good job showing how the system works.
[via MAKE]
And if this little demonstration sparked an interest, be sure to check out the amazing 2 disk documentary, Scratch.
