Heavy metal music in the context of "Deep Purple"

A microgenre is a specialized or niche genre, often used to describe narrowly defined subcategories within music, literature, film, or art. The term has been in use since at least the 1970s, particularly in the context of music, where it refers to specific stylistic offshoots of prominent genres, such as the many sub-subgenres of heavy metal and electronic music.

Originally, microgenres were labels retroactively applied by record collectors and dealers, often to increase the perceived value of rare or obscure recordings. Early examples include Northern soul, freakbeat, garage punk, and sunshine pop.

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.

A riff is a short, repeated motif or figure in the melody or accompaniment of a musical composition. Riffs are most often found in various genres of rock music (including punk and heavy metal music), as well as Latin, funk, and jazz, although classical music is also sometimes based on a riff, as in Ravel's Boléro. Riffs can be as simple as a tenor saxophone honking a simple, catchy rhythmic figure, or as complex as the riff-based variations in the head arrangements played by the Count Basie Orchestra.

David Brackett (1999) defines riffs as "short melodic phrases", while Richard Middleton (1999) defines them as "short rhythmic, melodic, or harmonic figures repeated to form a structural framework". Author Rikky Rooksby states: "A riff is a short, repeated, memorable musical phrase, often pitched low on the guitar, which focuses much of the energy and excitement of a rock 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.

Song structure is the arrangement of a song, and is a part of the songwriting process. It is typically sectional, which uses repeating forms in songs. Common piece-level musical forms for vocal music include bar form, 32-bar form, verse–chorus form, ternary form, strophic form, and the 12-bar blues. Popular music songs traditionally use the same music for each verse or stanza of lyrics (as opposed to songs that are "through-composed"—an approach used in classical music art songs). Pop and traditional forms can be used even with songs that have structural differences in melodies. The most common format in modern popular music is introduction (intro), verse, pre-chorus, chorus, verse, pre-chorus, chorus, bridge, and chorus, with an optional outro. In rock music styles, notably heavy metal music, there are usually one or more guitar solos in the song, often found after the middle chorus part. In pop music, there may be a guitar solo, or a solo performed with another instrument such as a synthesizer or a saxophone.

The foundation of popular music is the "verse" and "chorus" structure. Some writers use a simple "verse, hook, verse, hook, bridge, hook" method. Pop and rock songs nearly always have both a verse and a chorus. The primary difference between the two is that when the music of the verse returns, it is almost always given a new set of lyrics, whereas the chorus usually retains the same set of lyrics every time its music appears." Both are essential elements, with the verse usually played first (exceptions include "She Loves You" by The Beatles, an early example in the rock music genre). Each verse usually employs the same melody (possibly with some slight modifications), while the lyrics usually change for each verse. The chorus (or "refrain") usually consists of a melodic and lyrical phrase that repeats. Pop songs may have an introduction and coda ("tag"), but these elements are not essential to the identity of most songs. Pop songs often connect the verse and chorus via a pre-chorus, with a bridge section usually appearing after the second chorus.

Throughout the history of the British Isles, the land that is now the United Kingdom has been a major music producer, drawing inspiration from church music and traditional folk music, using instruments from England, Scotland, Northern Ireland, and Wales. Each of the four countries of the United Kingdom has its own diverse and distinctive folk music forms, which flourished until the era of industrialisation when they began to be replaced by new forms of popular music, including music hall and brass bands. Many British musicians have influenced modern music on a global scale, and the UK has one of the world's largest music industries. English, Scottish, Irish, and Welsh folk music as well as other British styles of music heavily influenced American music such as American folk music, American march music, old-time, ragtime, blues, country, and bluegrass. The UK has birthed many popular music genres such as beat music, psychedelic music, progressive rock/pop, heavy metal, new wave, industrial music, and drum 'n' bass.

In the 20th century, influences from the music of the United States, including blues, jazz, and rock and roll, were adopted in the United Kingdom. The "British Invasion"—spearheaded by Liverpool band the Beatles, often regarded as the most influential band of all time—saw British rock bands become highly influential around the world in the 1960s and 1970s. Pop music, a term which originated in Britain in the mid-1950s as a description for "rock and roll and the new youth music styles that it influenced", was developed by British artists like Black Sabbath, the Beatles and the Rolling Stones, whom among other British musicians led rock and roll's transition into rock music.

The culture of the United States encompasses various social behaviors, institutions, and norms, including forms of speech, literature, music, visual arts, performing arts, food, sports, religion, law, technology, as well as other customs, beliefs, and forms of knowledge. American culture has been shaped by the history of the United States, its geography, and various internal and external forces and migrations.

America's foundations were initially Western-based, and primarily English-influenced, but also with prominent French, German, Greek, Irish, Italian, Scottish, Welsh, Jewish, Polish, Scandinavian, Spanish and Portuguese regional influences. However, non-Western influences, including African and Indigenous cultures, and more recently, Asian cultures, have firmly established themselves in the fabric of American culture as well. Since the United States was established in 1776, its culture has been influenced by successive waves of immigrants, and the resulting "melting pot" of cultures has been a distinguishing feature of its society. Americans pioneered or made great strides in musical genres such as heavy metal, rhythm and blues, jazz, gospel, country, hip hop, and rock 'n' roll. The "big four sports" are American football, baseball, basketball, and ice hockey. In terms of religion, the majority of Americans are Protestant or Catholic, with a growing irreligious population. American cuisine includes popular tastes such as hot dogs, milkshakes, and barbecue, as well as many other class and regional preferences. The most commonly used language is English; while no law designates it official, a 2025 executive order declares English the official language. Distinct cultural regions include New England, Mid-Atlantic, the South, Midwest, Southwest, Mountain West, and Pacific Northwest.

Folk metal is a fusion genre of heavy metal music and traditional folk music that developed in Europe during the 1990s. It is characterised by the widespread use of folk instruments and, to a lesser extent, traditional singing styles (for example, Dutch Heidevolk, Danish Sylvatica and Spanish Stone of Erech). It also sometimes features soft instrumentation influenced by folk rock.

The earliest folk metal bands were Skyclad from England and Cruachan from Ireland. Skyclad's debut album The Wayward Sons of Mother Earth was released in 1991 and would be considered a thrash metal album with some folk influences, unlike Cruachan’s early work which embraced the folk element as a defining part of their sound. It was not until 1994 and 1995 that other early contributors in the genre began to emerge from different regions of Europe and beyond. Among these early groups, the German band Subway to Sally spearheaded a different regional variation that over time became known as medieval metal. Despite their contributions, folk metal remained little known with few representatives during the 1990s. It was not until the early 2000s when the genre exploded into prominence, particularly in Finland with the efforts of such groups as Finntroll, Ensiferum, Korpiklaani, Turisas, and Moonsorrow.

Authenticity is a concept of personality in the fields of psychology, existential psychotherapy, existentialist philosophy, and aesthetics. In existentialism, authenticity is the degree to which a person's actions are congruent with their values and desires, despite external pressures to social conformity. The conscious self comes to terms with the condition of Geworfenheit, of having been thrown into an absurd world (without values and meaning) not of their own making, thereby encountering external forces and influences different from and other than the Self. Authenticity has emerged as a central concept in contemporary models of well-being and the good life, serving as a foundational principle in many leading psychological frameworks. A person’s lack of authenticity is considered bad faith in dealing with other people and with one's self; thus, authenticity is in the instruction of the Oracle of Delphi: “Know thyself.” Concerning authenticity in art, the philosophers Jean Paul Sartre and Theodor Adorno held opposing views and opinions about jazz, a genre of American music; Sartre said that jazz is authentic and Adorno said that jazz is inauthentic. Many musical subcultures require artistic authenticity, lest the community consider an artist to be a poseur for lacking authenticity (creative, musical, or personal); artistic authenticity is integral to many genres of music, including but not limited to genres of rock (such as punk rock and heavy metal), club music (such as house and techno), and hip-hop.

In the 18th century, Romantic philosophers recommended intuition, emotion, and a connection to Nature as the necessary counterbalances to the intellectualism of the Age of Enlightenment. In the 20th century, Anglo–American preoccupations with authenticity centered on the writings of existentialist philosophers whose native tongue is not English; therefore, the faithful, true, and accurate translation of the term existentialism was much debated, to which end the philosopher Walter Kaufmann assembled a canon of existentialist philosophers. Kaufmann's canon includes the Dane Søren Kierkegaard (1813–1855), the German Martin Heidegger (1889–1976), and the Frenchman Jean-Paul Sartre (1905–1980). For these existentialists, the conscious Self comes to terms with existence (being and living) in an absurd, materialist world featuring external forces, e.g. Geworfenheit (Thrown-ness), and intellectual influences different from and other than the Self.