US PATENT SUBCLASS 968 / 821-- .~.~ Using electromechanical driving, e.g., of optical scanned recordings, etc. (electrophonic musical instruments in which tones are generated by electromechanical means, e.g., by using pickup means for reading recorded waves, etc. G10H 3/00) [G04F 5/02D]

US PATENT SUBCLASS 968 / 821
.~.~ Using electromechanical driving, e.g., of optical scanned recordings, etc. (electrophonic musical instruments in which tones are generated by electromechanical means, e.g., by using pickup means for reading recorded waves, etc. G10H 3/00) [G04F 5/02D]

968 /	HD	HOROLOGY

817	DD	APPARATUS FOR PRODUCING PRESELECTED TIME INTERVALS FOR USE AS TIMING STANDARDS (generating clock signals for electric digital computers G06F 1/04; regulating frequency in general H03C, L) [G04F 5/00] {6}
818	DD	.~ Metronomes (periodic signalization by acoustic signals in general subclass 218) [G04F 5/02] {3}
821		.~.~ Using electromechanical driving, e.g., of optical scanned recordings, etc. (electrophonic musical instruments in which tones are generated by electromechanical means, e.g., by using pickup means for reading recorded waves, etc. G10H 3/00) [G04F 5/02D]