Electrophonic instruments are those having electron tubes, gas tubes, or transistors. The difference between conventional-mechanical and electrophonic instrs. is that the tones of the latter are transmitted through electrical circuits ending in transducers. According to their system of tone generation, they may be classified as follows: 1) electromechanical, 2) electroacoustical, 3) electronic. The first category includes those instrs. with electrostatic, electromagnetic, or photoelectric tone…