This comes via commenter Muu, and it's probably easier to explain through watching, but here goes: In the above clip, MIDI is being used to convey musical notes and as art. The individual who created this arranges all the music himself and then pipes it through a program called Music Animation Machine player. The response to these clips has been tremendous, encouraging the creator to churn out more. Actually quite amazing stuff! Hit the "more >>" for, well, more.