A musical instrument including a note player operable to produce individual notes in a selected key, wherein a layout of the note player corresponds to a selected chord, in which three finger regions of the note player correspond to a root note, a third note, and a fifth note of the selected chord in the selected key.

A musical instrument including a note player operable to produce individual notes in a selected key, wherein a layout of the note player corresponds to a selected chord, in which three finger regions of the note player correspond to a root note, a third note, and a fifth note of the selected chord in the selected key.

A musical instrument with two or more classes of pitches where at least one class is a diminished chord extended over an arbitrary number of octaves, and another class is another chord extended over the same span of octaves. The pitches of the second class of pitches are interlaced with the pitches of the diminished chord of the first class of pitches. Additional classes are chords similarly interlaced with other classes, with one class of any interlaced pair of classes being a diminished chord.

An input device accepts user input and generates data indicative of notes, such as MIDI data. The input device includes a set of chord keys and a set of melody keys. A desired scale is selected, and the chord keys and melody keys are configured to utilize notes associated with that scale. The chord keys may be representative of all non-inverted chords associated with that scale. Inverted chords may be accessed using other keys or key combinations. Upon activation of an individual chord key, MIDI data representative of the notes in that chord is generated. Upon activation of an individual melody key, MIDI data representative of a single note from the scale is generated. Conflicts between notes associated with activated and released keys are resolved. Keys illuminated with a color associated with a particular note facilitate user recognition of that note in the chord keys and melody keys.