Abstract: Display apparatus provides for concurrent visual display and audible reproduction of musical notes individually or in plural. In one embodiment, a top octave generator operates responsively to an input signal having a characteristic which is variable in accordance with the relative positioning of visual display components of the apparatus. In a second embodiment a tone generator provides top octave and lower octave signals and selection is made for audible reproduction by a switching arrangement responsive to relative positioning of visual display components.

Abstract: A musical information display device includes first and second relatively rotatable members, the first member bearing spaced musical indicia and the second member including apertures registrable with the first member indicia on such rotation and aperture-closing elements, each operable independently of the condition of closure of the remainder of such elements. The musical indicia are arranged in such progression as the chromatic scale and numeric identifiers are associated with the aperture-closing elements and are arranged in sequential order to be displayed selectively on operation of the aperture-closing elements.