The Miracle Teaching System was made by Mindscape. My version included a French version and a English version. It is not only the language that is different but also the indications. The French version has: do, re, mi, etc. while the English version has: a, b, c, d, e, f and g.
The system has an adapter, a footpedal, an headset and a wire that links your keyboard with your NES. You can also choose not to link it to the NES and play it as a normal keyboard.