This is a preview of a new cursor-controlled granular synthesis feature in Photosounder, an application that lets you treat audio graphically.
Here’s what the developer has to say about it:
This video shows the work in progress that is live synthesis in Photosounder. At the moment the latest (unreleased) build of Photosounder can synthesise directly what’s under the mouse cursor, meaning you can play a sound at any rate without changing the pitch.
In the future it will a lot do more using the same synthesis technique. The first public release containing this feature will be released in a few weeks. Also at some point the mouse cursor is out of sync with what you hear, that has to do with the video recording software being out of sync, not Photosounder.
Original track is James Brown’s Cold Sweat