Guitars...

An electric guitar is a guitar that uses the principle of electromagnetic induction to convert vibrations of its metal strings into electric signals. Since the generated signal is too weak to drive a loudspeaker, it is amplified before sending it to a loudspeaker. Since the output of an electric guitar is an electric signal, the signal may easily be altered using electronic circuits to add colour to the sound. Often the signal is modified using effects such as reverb and distortion. Conceived in 1931, the electric guitar became a necessity as jazz musicians sought to amplify their sound. Since then, it has evolved into a stringed musical instrument capable of a multitude of sounds and styles. It served as a major component in the development of rock and roll and countless other genres of music.