An electric guitar is a guitar using pickups to convert its metal string vibration into electricity. This is amplified with an instrument amplifier. The output is altered with guitar effects such as reverb or distortion. The earliest electric guitars were hollow bodied acoustic instruments with tungsten steel pickups made by Rickenbacker in 1931. The electric guitar was a key instrument in the development of musical styles that emerged since the late 1940s, such as Chicago blues, early rock and roll and rockabilly, and 1960s blues rock. It is used in almost every popular music genre.

There has always been a quest for louder instruments. The guitar was a good candidate for amplification due to its acoustic properties and for its potential as a polyphonic solo instrument. The need for an amplified guitar became apparent during the big band era, as orchestras increased in size: particularly when guitars had to compete with large brass sections. The first electric guitars used in jazz were hollow archtop acoustic guitar bodies with electromagnetic transducers. By 1932 an electrically amplified guitar was commercially available. An early commercially successful solid-body electric guitar was the Fender Esquire in 1950.

Electric guitars were originally designed by luthiers, guitar makers, electronics enthusiasts, and instrument manufacturers. Guitar innovator Les Paul experimented with microphones attached to guitars. Some of the earliest electric guitars adapted hollow bodied acoustic instruments and used tungsten pickups. An electrically amplified guitar was developed by George Beauchamp in 1931. Commercial production began in late summer of 1932 by Electro-Patent-Instrument Company Los Angeles, a partnership of Adolph Rickenbacker, Paul Barth and George Beauchamp, the inventor. The wooden body of the prototype was built by Harry Watson, a craftsman who had worked for the National Resophonic Guitar Company (where the men met). By 1934 the company was renamed Rickenbacker Electro Stringed Instrument Company.

The earliest documented performance with an electrically amplified guitar was in 1932, by Gage Brewer. The Wichita, Kansas-based musician had an Electric Hawaiian A-25 (Fry-pan, lap-steel) and a standard Electric Spanish from George Beauchamp of Los Angeles, California. Brewer publicized his new instruments in an article in the Wichita Beacon, October 2, 1932 and through performances that month. Brewer's original 1932 Ro-Pat-In Electro Spanish guitar can currently be viewed at the Wichita-Sedgwick County Historical Museum.

Source:  Wiki