<P> In pop and rock music, the electric guitar is often used in two roles: as a rhythm guitar, which plays the chord sequences or progressions, and riffs, and sets the beat (as part of a rhythm section); and as a lead guitar, which provides instrumental melody lines, melodic instrumental fill passages, and solos . In a small group, such as a power trio, one guitarist switches between both roles . In larger rock and metal bands, there is often a rhythm guitarist and a lead guitarist . </P> <P> Many experiments at electrically amplifying the vibrations of a string instrument were made dating back to the early part of the 20th century . Patents from the 1910s show telephone transmitters were adapted and placed inside violins and banjos to amplify the sound . Hobbyists in the 1920s used carbon button microphones attached to the bridge; however, these detected vibration from the bridge on top of the instrument, resulting in a weak signal . With numerous people experimenting with electrical instruments in the 1920s and early 1930s, there are many claimants to have been the first to invent an electric guitar . </P> <P> Electric guitars were originally designed by acoustic guitar makers and instrument manufacturers . Some of the earliest electric guitars adapted hollow - bodied acoustic instruments and used tungsten pickups . The first electrically amplified guitar was designed in 1931 by George Beauchamp, the general manager of the National Guitar Corporation, with Paul Barth, who was vice president . The maple body prototype for the one - piece cast aluminium "frying pan" was built by Harry Watson, factory superintendent of the National Guitar Corporation . Commercial production began in late summer of 1932 by the Ro - Pat - In Corporation (Electro - Patent - Instrument Company), in Los Angeles, a partnership of Beauchamp, Adolph Rickenbacker (originally Rickenbacher), and Paul Barth . In 1934, the company was renamed the Rickenbacker Electro Stringed Instrument Company . In that year Beauchamp applied for a United States patent for an Electrical Stringed Musical Instrument and the patent was later issued in 1937 . </P> <P> By early - mid 1935, Electro String Instrument Corporation had achieved mainstream success with the A-22 "Frying Pan" steel guitar, and set out to capture a new audience through its release of the Electro - Spanish Model B and the Electro - Spanish Ken Roberts which was the first full 25" scale electric guitar ever produced . </P>

Who invented the first solid-body electric guitar for which guitar company
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