Desktop Piano Keyboard is a small and lightweight software that will let you play the piano on your desktop. Using the MIDI capabilities of your sound card this polyphonic desktop keyboard synthesizer has 128 different voices and sound effects.
You can play the piano using either the keyboard or your mouse, but using your keyboard gives you a much better experience.
Don’t expect it to play your piano notes or give you piano lessons, but you could definitely use it to while your time playing some great or annoying music ;).
Desktop Piano Keyboard is a freeware, so you don’t need to worry about paying anything.