A 128-note MIDI-range monophonic musical keyboard instrument (100) includes an octave keypad (106) with eleven keys arranged in an analog clock face format for octave selection with the thumb of one hand, a pitch keypad (108) with twelve pitch keys similarly disposed in a clockface arrangement around a central omnivalent thirteenth key (128), enabling the nondisjointed sounding of nonadjacent notes with the thumb of the other hand. Spatial manipulation of the device, such as tilting and jabbing, can switch octaves and activate other functions, enabling one-handed operation and overcoming small-screen space limitation. Aside from producing typical electronic piano or synthesizer sounds, the device can sing in human voice an extended monosyllabic solfege covering all twelve pitch families of the common chromatic 12-tone even-tempered scale. A pictograph-based music notation (156) mirrors the circular geometry of the pitch and octave keyboards and facilitates the intuitive reading and playing of a melody.