A process and a system are disclosed for some embodiments of the invention that map MIDI signals in a manner which always puts the harmony and melody octaves of an electronic MIDI keyboard in perfect pitch for a user of the keyboard. The process of some embodiments includes (i) receiving a selection of a key signature, (ii) receiving a selection of a scale, (iii) organizing the left side octave(s) (“chord” side) into a chord generator that places all scale tones on white keys and applies a chord effect to each white key, relative to the scale tone position, and (iv) organizing the right side octave(s) (“melody” side) into a melody lock that provides multiple settings for mapping the seven scale tones onto white keys.