A synthesizer is an electronic musical instrument that generates audio signals that can be converted to audible sound. Not only can synthesizers imitate both conventional instruments and natural sounds, but they can also produce novel sounds. They can be controlled with a variety of devices including computers and piano-like keyboards.
Synthesizers have dramatically changed both the creation process and the sound of music, including both art music and popular music, since they came into widespread use in the early 1970s. Their use has become so pervasive, in fact, that today little Western music is created without them.