Editor: Have you ever wished that there was some way to easily play notes on your Synthesizer, without leaving the computer? I'm sure everyone has spend many SleepLess nights because of this problem, so now I introduce to you - Virtual Piano! VPiano allows you to play your synth by making the computer keyboard into a 4-octave piano keyboard. Sure, you're probably not going to be able to play classical music this way, but you can experiment and have fun using a very different interface than normal, which can sometimes help to stimulate the creative process.
You must have a MIDI output device, as well as a sound source to use this program (anything from a Soundblaster to a Midi timePiece will do); then just run the program, configure the MIDI devices, and start jamming!