So this is not my former teacher Andy Best, this is another Andy Best. 
I have been developing a video step sequencer in OpenFrameworks recently and I thought I’d share a video of my progress so far.
Essentially, it consists of a camera pointing at a printed 16×16 grid. The grid represents 16 semitones on the vertical axis and 16 steps (quater notes) on the horizontal axis. Objects can then be placed in the squares (or they can be coloured in) to activate that particular note.
Andy’s sequencer is principally really basic stuff and you can do same thing with Max/Msp/Jitter, but since OpenFrameWorks is much more flexible for coders, I find this solution quite interesting. Also problem with Jitter is that external cam-order usually refuses to co-operate on windows enviroment.
Notice: In the future similar stuff is found in my http://diysoundmachines.blogspot.com/ blog.