One of my first graduate classes was Interaction Design, in which I planned an interactive project that would involve synching the projected video playback of a person dancing with the beat signature of a given song with a little programming in MaxMSP/Jitter.
The project involved recording my friend dancing to several tracks that were selected in advance because of their seemingly typical beat signatures, one hip hope track, one house track and one R&B track, my rationale being that these types of songs are most used in clubs and the playback would be seamless as the trakcs changed over hours and hours.
The following Youtube clip of Krystal, syncs up perfectly with Snoop Dogg's "Drop it Like Its Hot" with a little tweaking of the play and pause buttons
This clip syncs perfectly with a house track, "Island Breeze" by Pashka".
I kept a chronicle of the design process from planning to building my sort of prototype on my first semester graduate blog. You can access it here. Though I was unable to comprehend MaxMSP well enough then to complete the project, I've gathered a lot of information through MeetUps and private study to help put me on the right track to devlepoing this functionality using Jitter and perhaps OpenFrameworks as programming solutions.