This is a software tool developed to focus more on the melody than the disappointment of hitting wrong notes during a performance.
Selecting a musical scale maps the notes on black keys, on to the white keys of your MIDI Keyboard. Create your musical scale palette and let the melody flow. You really can not go wrong with this!
Once you are happy with your performance and record it, it is possible to go back and simply play with the scale itself and discover the rhythm of your melody under different musical scales.