Then, there are 2 ways to use Visual Piano:

With a Midi compatible keyboard or a synthesizer:

Required material : A Midi connector cable (Y) and 5-pin Midi cables (1 or 2). There are 3 possible configurations depending on your material.

With a Non Midi compatible keyboard or a real acoustic piano:

Required material : Nothing.
In this case, it would be better to relocate the computer to where your instrument is located, or vice versa !