electronic and scientific (not for medical use) equipment, namely electroacoustic transducers, sensors for amplifying musical sounds generated on musical instruments; data processors; data micro processors; cinematographic films and prerecorded video cassettes featuring musical, theatrical, opera performances; sound production equipment, namely loudspeakers, amplifiers, microphones, tuners, mixers, controllers; radios; televisions; temperature, pressure displacement, signal lock controllers; signaling equipment, namely electronic controls for signaling equipment; sound system components for electrical and electronic installations; electrical remote controls for sound systems; teaching apparatus, namely card readers, console mounted video monitors, controls for multiple teaching programs; sound sequencers; signal processing apparatuses, namely digital signal processors, audio signal processors; signal delay circuitry; sound mixing apparatus and tables; recording media replay decks; blank recording media, namely magnetic, optical, electronic, digital, and audio recorders for recording sounds, images, data, and computer programs; prerecorded audio and video discs, hard discs, diskettes, tape, cartridges, and compact discs featuring musical, theatrical, opera performances; electrical wires, magnetic coded cards; data encoders; data processors; electronic data processing equipment, namely encoders, decoders, controllers, and computers for use in the audiovisual and sound production field; computer peripherals, namely consoles, monitors, screens, readers, keyboards, printers, interfaces, modems, memories and scanners for computers; audio and video receivers; projection apparatus, namely overhead projectors, projections screens and slides; tape recorders; sound amplifiers; loudspeakers; loudspeaker enclosures; loudspeaker components; and electronic servocontrol circuitry for controlling loudspeakers; electronic circuitry for controlling amplification; electronic circuitry for volume correction voltage spike limiters; computer software for programming musical instruments; electronic and digital tuners; video cameras; video recorders; luminous and mechanical signs, signboards, and panels; film and slide viewers; recording media, namely floppy discs and hard magnetic discs, magnetic tapes, compact discs, video discs, and filing devices specially adapted therefor; ear pieces and headsets; sirens; megaphones; sound level meters; low-frequency electronic equipment, namely electrical and electronic circuitry and components for conducting, distributing, transforming, accumulating, adjusting, and controlling electric current