Synthesia is a popular piano program made by Nicholas Piegdon. It was the original program that was widely used to play black MIDIs. Nowadays with better alternatives such as Piano From Above, MIDITrail, etc. Synthesia is now only used to play smaller pieces, and/or is used as a "challenge" to have the least lag when playing bigger pieces. The program's latest released revision is 10.x. Since the latest release is now a shareware, you need to pay in order to play MIDIs that are not pre-installed and to get the "Learning Pack," which allows for better learning with note labels, etc.