From Flextron Bt.:
Play this on-screen piano using your computer keyboard or mouse. PC 73 is a stylish and easy to play, free virtual piano and synthesizer. By default, the sound is generated by the inbuilt General Midi software synthesizer of the Windows operating system. In general, you can use PC 73 on-screen piano as a virtual midi controller to control any General Midi compatible software or hardware synthesizer (midi output device). You can control 128 General Midi musical instruments and 47 percussion sounds: all instruments from organ to vibraphone, from guitar to harp, from synthesizer sounds to acoustic drums. The sleek graphical interface of this on-screen piano features 73 realistic piano keys with dynamic shadows. Use PC 73 Virtual Piano Keyboard on your PC in stand-alone mode for checking musical notes, intervals, chords, tuning instruments by ear, testing simple melodies and musical ideas, or jam along with one of our backing band programs (e.g. ChordPulse Lite) when no real piano keyboard is available. By playing along with a programmable background accompaniment, the on-screen piano allows you to experiment with music styles and arrangements in a unique and inspiring way. This freeware application runs on Windows XP, Windows Vista and Windows 7 computers.