Electronic music generally refers to music created using electronic equipment. That is, any sound created by the means of electrical signals could be called electronic.
Production of such music involves the use of power amplifiers as well as loudspeakers. Instruments such as synthesizer and electronic organ are examples of this. In these, oscillators produce electric signals with same frequencies as musical notes. The signals are then pushed to loud speakers. Subsequently, they cause the loudspeaker to vibrate, and produce musical sounds.
History records that the earliest electronic equipment was invented sometime in 1897. It was called the teleharmonium, believed to have been developed by Thaddeus Cahill. But since it weighed around seven tonnes, the instrument was inconvenient for use. The first practical electronic musical instrument is considered to be the theremin, invented by Leon Theremin in 1919 – 1920. Since then, many more equipments have been developed till date.