Hard rock in the context of "Arena rock"

An instrumental, instrumental music, or sometimes "instrumental song" is music without any vocals, although it might include some inarticulate vocals, such as shouted backup vocals in a big band setting. Through semantic widening, a broader sense of the word "song" may refer to instrumentals. The music is primarily or exclusively produced using musical instruments. An instrumental can exist in music notation, after it is written by a composer; in the mind of the composer (especially in cases where the composer themselves will perform the piece, as in the case of a blues solo guitarist or a folk music fiddle player); as a piece that is performed live by a single instrumentalist or a musical ensemble, which could range in components from a duo or trio to a large big band, concert band or orchestra.

In a song that is otherwise sung, a section that is not sung but which is played by instruments can be called an instrumental interlude, or, if it occurs at the beginning of the song, before the singer starts to sing, an instrumental introduction. If the instrumental section highlights the skill, musicality, and often the virtuosity of a particular performer (or group of performers), the section may be called a "solo" (e.g., the guitar solo that is a key section of heavy metal music and hard rock songs). If the instruments are percussion instruments, the interlude can be called a percussion interlude or "percussion break". These interludes are a form of break in the song.

Distortion and overdrive are forms of audio signal processing used to alter the sound of amplified electric musical instruments, usually by increasing their gain, producing a "fuzzy", "growling", or "gritty" tone. Distortion is most commonly used with the electric guitar, but may be used with other instruments, such as electric bass, electric piano, synthesizer, and Hammond organ. Guitarists playing electric blues originally obtained an overdriven sound by turning up their vacuum tube-powered guitar amplifiers to high volumes, which caused the signal to distort. Other ways to produce distortion have been developed since the 1960s, such as distortion effect pedals. The growling tone of a distorted electric guitar is a key part of many genres, including blues and many rock music genres, notably hard rock, punk rock, hardcore punk, acid rock, grunge and heavy metal music, while the use of distorted bass has been essential in a genre of hip hop music and alternative hip hop known as "SoundCloud rap".

The effects alter the instrument sound by clipping the signal (pushing it past its maximum, which shears off the peaks and troughs of the signal waves), adding sustain and harmonic and inharmonic overtones and leading to a compressed sound that is often described as "warm" and "dirty", depending on the type and intensity of distortion used. The terms distortion and overdrive are often used interchangeably; where a distinction is made, distortion is a more extreme version of the effect than overdrive. Fuzz is a particular form of extreme distortion originally created by guitarists using faulty equipment (such as a misaligned valve (tube); see below), which has been emulated since the 1960s by a number of "fuzzbox" effects pedals.

Chicago blues is a form of blues music that developed in Chicago, Illinois. It is based on earlier blues idioms, such as Delta blues, but is performed in an urban style. It developed alongside the Great Migration of African Americans of the first half of the twentieth century. Key features that distinguish Chicago blues from the earlier traditions, such as Delta blues, are the prominent use of electrified instruments (especially the electric guitar), and the use of electronic effects, such as distortion and overdrive.

Muddy Waters, often acknowledged as the “father” of Chicago blues, was a colleague of Delta blues musicians Son House and Robert Johnson. He migrated to Chicago in 1943, joining the established Big Bill Broonzy, where they developed a distinct style of the Chicago blues, which hit its peak around the late 1940s and early 1950s. Joined by artists such as Willie Dixon, Howlin' Wolf, and John Lee Hooker, Chicago blues reached an international audience by the late 1950s and early 1960s, directly influencing not only the development of early rock and roll musicians such as Chuck Berry and Bo Diddley, but also reaching across the Atlantic to influence both British blues and early hard rock acts such as Eric Clapton, the Rolling Stones, and Led Zeppelin. Prominent record labels such as Vee-Jay Records and Chess Records helped promote and spread the style. The Chicago Blues Festival has been held annually since 1984, on the anniversary of Muddy Waters' death, as a means of preserving and promoting Chicago blues.

Acid rock is a loosely defined type of rock music that evolved out of the mid-1960s garage punk movement and helped launch the psychedelic subculture. While the term has sometimes been used interchangeably with "psychedelic rock", acid rock also specifically refers to a more musically intense, rawer, or heavier subgenre or sibling of psychedelic rock. Named after lysergic acid diethylamide (LSD), the style is generally defined by heavy, distorted guitars and often contains lyrics with drug references and long improvised jams.

Compared to other forms of psychedelic rock, acid rock features a harder, louder, heavier, or rawer sound. Much of the style overlaps with 1960s garage punk, proto-metal, and early heavy, blues-based hard rock. It developed mainly from the American West Coast, where groups did not focus on the novelty recording effects or whimsy of British psychedelia; instead, the subgenre emphasized the heavier qualities associated with both the positive and negative extremes of the psychedelic experience.

Grunge (originally known as the Seattle Sound) is an alternative rock genre and subculture that emerged during the mid-1980s in the U.S. state of Washington, particularly in Seattle and Olympia, and other nearby cities. Grunge fuses elements of punk rock and heavy metal, and features the distorted electric guitar sound used in both genres, as well as bass guitar, drums, and vocals. Grunge also incorporates influences from indie rock bands such as Sonic Youth, Pixies, and Dinosaur Jr. Lyrics are typically angst-filled and introspective, often addressing themes such as social alienation, self-doubt, abuse, neglect, betrayal, social isolation and emotional isolation, addiction, psychological trauma, and a desire for freedom.

The early grunge movement revolved around Seattle's independent record label Sub Pop and the region's underground music scene, with local bands such as Green River, the Melvins, and Mudhoney playing key roles in the genre's development. Sub Pop marketed the style shrewdly, encouraging media outlets to describe the Seattle sound as "grunge"; the style became known as a hybrid of punk and metal. By the early 1990s, its popularity had spread, with similar sounding bands appearing in California, then emerging in other parts of the United States and Australia, building strong followings and signing major record deals. Grunge broke through into the mainstream in the early-to-mid-1990s, led by Nirvana's Nevermind in 1991, and followed by other crossover successes including Pearl Jam's Ten, Soundgarden's Badmotorfinger, and Alice in Chains' Dirt. The success of these bands boosted the popularity of alternative rock, eventually making grunge the most popular form of hard rock music during the 1990s.

The Beatles were an English rock band formed in Liverpool in 1960. The core lineup of the band comprised John Lennon, Paul McCartney, George Harrison and Ringo Starr. They are widely regarded as the most influential band in popular music and were integral to the development of 1960s counterculture and the recognition of popular music as an art form. Rooted in skiffle, beat and 1950s rock 'n' roll, their sound incorporated elements of classical music and traditional pop in innovative ways. The band also explored music styles ranging from folk and Indian music to psychedelia and hard rock. As pioneers in recording, songwriting and artistic presentation, the Beatles revolutionised many aspects of the music industry and were often publicised as leaders of the era's youth and sociocultural movements.

Led by primary songwriters Lennon and McCartney, the Beatles evolved from Lennon's previous group, the Quarrymen, and built their reputation by playing clubs in Liverpool and Hamburg, Germany, starting in 1960. The core trio of Lennon, McCartney and Harrison, together since 1958, went through a succession of drummers before inviting Starr to join them in 1962. Manager Brian Epstein moulded them into a professional act, and producer George Martin developed their recordings, greatly expanding their domestic success after they signed with EMI and achieved their first hit, "Love Me Do", in late 1962. As their popularity grew into the intense fan frenzy dubbed "Beatlemania", the band acquired the nickname "the Fab Four". By early 1964, the Beatles were international stars and had achieved unprecedented levels of critical and commercial success. They became a leading force in Britain's cultural resurgence, ushering in the British Invasion of the United States pop market. They soon made their film debut with A Hard Day's Night (1964).

A down-the-hole drill, usually called DTH by most professionals, is basically a jackhammer screwed on the bottom of a drill string. The fast hammer action breaks hard rock into small cuttings and dust that are evacuated by a fluid (air, water or drilling mud). The DTH hammer is one of the fastest ways to drill hard rock. The system is thought to have been invented independently by Stenuick Frères in Belgium and Ingersoll Rand in the USA in the mid-1950s.

The Rolling Stones are an English rock band formed in London in 1962. Active for over six decades, they are one of the most popular, influential, and enduring bands of the rock era. In the early 1960s, the band pioneered the gritty, rhythmically driven sound that came to define hard rock. Their first stable line-up consisted of vocalist Mick Jagger, guitarist Keith Richards, multi-instrumentalist Brian Jones, bassist Bill Wyman, and drummer Charlie Watts, after pianist Ian Stewart was side-lined by their manager Andrew Loog Oldham. During their early years, Jones was the primary leader. Oldham encouraged them to write their own songs. The Jagger–Richards partnership soon became the band's primary songwriting and creative force.

Rooted in blues and early rock and roll, the Rolling Stones started out playing cover versions and were at the forefront of the British Invasion in 1964, becoming identified with the youthful counterculture of the 1960s. They then found greater success with their own compositions: "(I Can't Get No) Satisfaction", "Get Off of My Cloud" (both 1965) and "Paint It Black" (1966) became international number-one hits. Aftermath (1966), their first album to be entirely of original material, is often considered to be the most important of their early albums. In 1967, they had the double-sided hit "Ruby Tuesday"/"Let's Spend the Night Together" and experimented with psychedelic rock on Their Satanic Majesties Request. By the end of the 1960s, they had returned to their rhythm and blues-based rock sound, with hit singles "Jumpin' Jack Flash" (1968) and "Honky Tonk Women" (1969), and albums Beggars Banquet (1968), featuring "Sympathy for the Devil" and "Street Fighting Man", and Let It Bleed (1969), featuring "You Can't Always Get What You Want" and "Gimme Shelter".