From Wikipedia, the free encyclopedia
An electric instrument (which, in the broadest sense, includes both electrically amplified acoustic instruments and electronic musical instruments) is one in which a loudspeaker is used as the main sound generator.
Looked at in this way, the paper cone of the loudspeaker acts in similar fashion to the membranophone family of percussion instruments. However, instead of the vibrations of the membrane being initiated by striking it, they are controlled by the electromagnetic field in the speaker's coil.
When a microphone or a pickup built into or attached to a musical instrument responds to incoming sound waves, a varying electric signal is produced, which is sent to the coil and reproduced as sound again by the speaker.
When an electronic musical instrument creates a varying electronic signal in its circuitry, this signal is sent to the loudspeaker and heard for the first time.