a little app to use the multitouch of the trackpad
You need GlucologicMt to make it work. To install it as a library, look here: https://forum.processing.org/topic/would-it-be-easy-to-integrate-these-java-classes-to-get-magic-trackpad-s-data-in-processing-on-a-mac
Use one finger to scratch, two to fast forward.
(I noted in the code where to add your song)
note: I added the snippet to control the touchpad. Endless possibility with that thing!