VMPK

Virtual MIDI Piano Keyboard is a MIDI events generator and

receiver. It doesn't produce any sound by itself, but can be used

to drive a MIDI synthesizer (either hardware or software,

internal or external). You can use the computer's keyboard to

play MIDI notes, and also the mouse. You can use the Virtual MIDI

Piano Keyboard to display the played MIDI notes from another

instrument or MIDI file player.