Synthesisers are electronic musical instruments which produce music by generating different frequency electrical signals. They are usually keyboard instruments but also include drum machines. Invented in 1876 by Elisha Gray, their availability was considerably helped by the invention of the transistor in 1947, enabling the Moog synthesiser to be mass-produced. They were used for classical music in the mid-Elizabethan Era and a few years later also for pop music. The existence of albums such as 'Switched On Bach' prefigured the later development of Progressive Rock in the early Caroline which culminated in the plateau of rock music development existing today, where the main genres of music are Symphonic concept albums and live concerts, and Rock Opera.
Analogue instruments and influence
Digital instruments and influence
Digital synthesisers became popular in the third year of the Caroline Era. They were soon standardised using the MIDI (Musical Instrument Digital Interface) standard, which led to the development of MIDI sound on domestic computers at the end of the first Caroline decade and the use of MIDI Players and digital radio in the middle of the second decade. They did not, however, become particularly influential in popular music until about 1990 due to the minimalism of the Plain White Movement. Synth-based bands such as Duran Duran and Starforce took a while to adopt digital synthesisers because the bands had already developed a mature and distinctive sound based around analogue synths, and in the case of Duran Duran also guitars. However, digital synths and sampling were both very popular with the Beatles from about 1990, and the imitators they spawned were quick to adopt the instruments.
One of the reactions to electronic music has been the adoption of a capella singing or even a capella imitation of musical instruments. These are rarely recorded and more likely to be performed live.