Abstract: An electronic Zimbelstern system in which a sequential counter actuates a set of self-damping circuits in a predetermined repeating sequence, the self-damping circuits each enabling a different set of sinusoidal tone sources in such relative amplitudes and with such relative rise and decay envelopes as to simulate the sounds of sequentially sounding bells of diverse fundamental frequencies when electro-acoustically reproduced.

Abstract: An electrical organ in which each of the keys of the organ is mechanically coupled to one single pole single throw electrical switch, and a plurality of said switches are each connected to a plurality of photoelectric tone sources through pulse shaping keying circuits, the keying circuits connected to each key switch being connected in a cascade circuit with the direct current potential source and the photocell of one of the tone sources, the other tone sources having photocells connected to the junctions of keying circuits in said cascade circuit. The tone circuits actuated by a given key of the organ may be at the same frequency or may comprise a chiff tone component or a noise-puff component, or may include a special decay circuit which activates a photocell modulated at a different pitch from the main-tone component.