After World War II, when tape recorders had been invented and were becoming popular, composers started to use them to make music. The tape recorder was needed for the performance. Composers used them to combine lots of different sounds. Sometimes it was music played on ordinary (acoustic) instruments which was then changed in some way by the tape recorder. Sometimes they took sounds from everyday life such as the sound of water, traffic noise or bird song. All these noises were put together in the way the composer wanted by using the tape recorder. Tapes of sounds were often cut into pieces, then the pieces were 'spliced' – put back together in a different order. The results were often very interesting, but there were problems. Some people asked: “Is it music?” Others thought it was boring to just look at a tape recorder during a concert instead of being able to watch live musicians play.
Composers in Paris were experimenting with electronic music in the 1940s. They called it “Musique concrète” because they used natural, concrete sounds. (“Concrete” in this sense meant the opposite of “abstract” music which was written down for performance). The sounds were played back at different speeds, combined in lots of ways, played backwards or played continuously (repeated in a 'loop'), or played into a mixer and re-recorded onto another tape recorder. The sounds could be filtered. Effects such as vibrato or echo could be added. Sometimes composers used synthesizers which were machines that could make electronic music in real time. They sounded more like normal instruments than the sound effects on a tape recorder.
Computers have often been used for composing electronic music. everything you here in music, is ether music made by a computer, and then added as a background to a song, along with the singing.
Composers who have used these ways of making music include John Cage (1912-1992), Bruno Maderna (1920-1973) and Karlheinz Stockhausen (b.1928). Very often composers combined electronic music with ordinary instruments being played.
In popular music, the use of electronics to create new sounds began in the 1960s. Producer Joe Meek and inventor Bob Moog both expanded the range of sounds that could be used in pop music, and by the end of that decade electronics had become accepted in the industry. In the next few years the work of people like Giorgio Moroder, Jean-Michel Jarre, Brian Eno and Kraftwerk made electronic music famous.
In the early 1980s electronic music became fashionable, and bands like New Order, The Human League, Pet Shop Boys and Depeche Mode became famous. Sometimes these bands would mix electronic music with rock music.
In the 21st Century electronics are so much a part of popular music that using it is no longer strange - in fact, many artists use nothing else.
A subgenre of electronic music is electronic dance music, or EDM. Electronic dance music is a form of electronica which is generally made with the intention of being danced to, thus making it generally club-friendly and often (but not always) up-tempo in nature. Whilst a lot of electronic genres are also classified as EDM, not all forms of electronic music fall within the specific category. Examples of EDM genres include post-disco, house, techno, Eurodance, trance, trip hop, drum and bass and dubstep, as well as several others.