(Not uploaded anywhere or anything else, work offline if you prefer)
Think of your keyboard as a piano where A-L are the white keys and Q-P the black keys (where applicable).
Use 1-9 to change octave
Use Z-M to transpose the keys (pressing V will set G as the 'Do (C)' and so on)
Should the sound stop, try hitting F5 or using another browser.
Original/Based on : http://edwardleuf.org/misc/twhat/
Modification by TrianguloY
