Abstract: A system is provided for adaptive demarcation of a selectively defined tonal scale on a musical instrument having a set of note actuators which span at least one musical octave. A scale acquisition portion acquires a tonal scale characterized at least by a predetermined mode and predetermined key signature, to define a predefined ordered series of tone components. The tone components are represented by different musical notes, and are successively separated in pitch by tonal intervals. A scale delineation portion coupled to the scale acquisition portion adaptively maps the tone components to a corresponding subset of the note actuators within at least one musical octave. A plurality of marker portions coupled respectively to the note actuators are selectively enabled according to the tone components' mapping to visually indicate the subset of note actuators corresponding thereto. Visual indication is thereby adaptively maintained for the note actuators of the acquired tonal scale.