This invention constitutes a set of devices that provides an approach to music instruction that is devoted particularly to demonstrating fundamental tonal properties of the musical octave. Novel shapes and sizes of both physical and virtual models are employed to represent these tonal properties in a vivid and graphical manner. Whether physical or virtual, each member of a given set of models is a portrayal that represents a particular amount of minimum tonal intervals of the musical octave. Physical models are in the form of blocks shaped to represent particular tonal intervals. Virtual models are images representing tonal intervals that are stored in computer memory and displayed on a computer screen. Assigned musical tones can be associated with individual displayed virtual images. Display and manipulation of these models (a) convey basic arithmetical or integral relationships of tonal intervals, (b) greatly enhance and stimulate both the understanding and the utilization of musical concepts, and (c) are entirely independent of conventional music notation.