Guitar tunings in the context of "Guitar chord"

An acoustic guitar is a musical instrument in the string family. When a string is plucked, its vibration is transmitted from the bridge, resonating throughout the top of the guitar. It is also transmitted to the side and back of the instrument, resonating through the air in the body, and producing sound from the sound hole. While the original, general term for this stringed instrument is guitar, the retronym 'acoustic guitar' – often used to indicate the steel stringed model – distinguishes it from an electric guitar, which relies on electronic amplification. Typically, a guitar's body is a sound box, of which the top side serves as a sound board that enhances the vibration sounds of the strings. In standard tuning the guitar's six strings are tuned (low to high) E₂ A₂ D₃ G₃ B₃ E₄.

Guitar strings may be plucked individually with a pick (plectrum) or fingertip, or strummed to play chords. Plucking a string causes it to vibrate at a fundamental pitch determined by the string's length, mass, and tension. (Overtones are also present, closely related to harmonics of the fundamental pitch.) The string causes the soundboard and the air enclosed by the sound box to vibrate. As these have their own resonances, they amplify some overtones more strongly than others, affecting the timbre of the resulting sound.

Grindcore is an extreme fusion genre of heavy metal and hardcore punk that originated in the mid-1980s, drawing inspiration from abrasive-sounding musical styles, such as thrashcore, crust punk, hardcore punk, extreme metal, and industrial. Grindcore is considered a more noise-filled style of hardcore punk while using hardcore's trademark characteristics such as heavily distorted, down-tuned guitars, grinding overdriven bass, high-speed tempo, blast beats, and vocals which consist of growls, shouts and high-pitched shrieks. Early groups such as England's Napalm Death are credited with laying the groundwork for the style. It is most prevalent today in North America and Europe, with popular contributors such as Brutal Truth and Nasum. Lyrical themes range from a primary focus on social and political concerns, to gory subject matter and black humor.

A trait of grindcore is the "microsong", far shorter than average for punk or metal. Several bands have produced songs that are only seconds in length. Many bands, such as Agoraphobic Nosebleed, record simple phrases that may be rhythmically sprawled out across an instrumental lasting only a couple of bars in length.

Nu metal (sometimes stylized as nü-metal, with a metal umlaut) is a subgenre of alternative metal that combines elements of heavy metal music with elements of other music genres such as hip hop, funk, industrial, and grunge. Nu metal rarely features guitar solos or other displays of musical technique and emphasizes rhythm with instrumentation that is heavily syncopated. Nu metal guitarists often use seven-string guitars that are down-tuned to produce a heavier sound. Vocal styles are often rhythmic and influenced by hip hop, and include singing, rapping, screaming and sometimes growling. DJs are occasionally featured to provide instrumentation such as sampling, turntable scratching and electronic background music. Nu metal is one of the key genres of the new wave of American heavy metal.

In the late 1980s and early 1990s, bands like Pantera, Helmet, and Faith No More were influential in the development of nu-metal with their groove metal and alternative metal styles. Korn is often credited as pioneering the subgenre in the mid-1990s with their self-titled debut album. Nu metal became popular in the late 1990s, with bands and artists such as Korn, Limp Bizkit, and Slipknot all releasing albums that sold millions of copies.