1) Electronic musical instrument 
The electrophone category was added to the Hornbostel-Sachs musical instrument classification system by Sachs in 1940, to describe instruments involving electricity. Sachs divided his 5th category into 3 subcategories: The last category includes instruments such as theremins or synthesizers, which he called radioelectric instruments. Francis Willi...[information system] The name Electrophone was used for a telephone-distributed audio system which operated in the United Kingdom between 1895 and 1926, relaying live theatre and music hall shows and, on Sundays, live sermons from churches via special headsets connected to conventional phone lines. This was similar to the French Theatrophon...
• (n.) An instrument for producing sound by means of electric currents.
any of a class of musical instruments in which the initial sound either is produced by electronic means or is conventionally produced (as by a ... [2 related articles]
E·lec'tro·phone noun [ Electro- + Greek 
The electrophones are the group of musical instruments in which sound is generated by electronic devices, vacuum valves or semiconductors.
electrophone An instrument (as a theremin) that produces musical tones by means of oscillating electric circuits; adjective, electrophonic; adverb, electrophonically.