Electric guitars, introduced in the 1930s, use an amplifier and a loudspeaker that both makes the sound of the instrument loud enough for the performers and audience to hear, and, given that it produces an electric signal when played, that can electronically manipulate and shape the tone using an equalizer (e.g., bass and treble tone controls) and a huge variety of electronic effects units, the most commonly used ones being distortion (or and reverb. Early amplified guitars employed a hollow body, but solid wood guitars began to dominate during the 1960s and 1970s, as they are less prone to unwanted acoustic feedback "howls". As with acoustic guitars, there are a number of types of electric guitars, including hollow body guitars, arch top guitars (used in jazz guitar, blues and rockabilly) and solid-body guitars, which are widely used in rock music.
The loud, amplified sound and sonic power of the electric guitar played through a guitar amp has played a key role in the development of blues and rock music, both as an accompaniment instrument (playing riffs and chords) and performing guitar solos, and in many rock sub genres, notably heavy metal music and punk rock. The electric guitar has had a major influence on popular culture. The guitar is used in a wide variety of musical genres worldwide. It is recognized as a primary instrument in genres such as blues, bluegrass, country, flamenco, folk, jazz,mariachi, metal, punk, reggae, rock, soul, and pop.