The Wheeled Piano is a kind of video MIDI séquencer which can read music roll.

The concept is quite easy to understand. With a webcam, you look at a music roll. If a hole (any dark color, in fact) cross the middle line between two graduations, the Wheeled piano is going to play the note until the hole leaves the line.

You quickly realize that it's possible to make music with anything just by filming around. Darks parts of the picture will be translate as a note if they cross the middle line. The problem is that it would be difficult to play the same composition several times.

What is needed to do that is regular movement of a specific pattern and an easy way to get this configuration is to use a turntable with a paper-disc.

A project by: http://citilab.eu/en/projects/vision
Read more at: http://www.citilabpro.eu/visionwiki/index.php?title=The_Wheeled_Piano