Popular music in the context of Tonic key

A music genre is a conventional category that identifies some pieces of music as belonging to a shared tradition or set of conventions. Genre is to be distinguished from musical form and musical style, although in practice these terms are sometimes used interchangeably.

Music can be divided into genres in numerous ways, sometimes broadly and with polarity, e.g., popular music as opposed to art music or folk music, or, as another example, religious music and secular music. Often, however, classification draws on the proliferation of derivative subgenres, fusion genres, and microgenres that has started to accrue, e.g., screamo, country pop, and mumble rap, respectively. The artistic nature of music means that these classifications are often subjective and controversial, and some may overlap. As genres evolve, novel music is sometimes lumped into existing categories.

Musical composition can refer to an original piece or work of music, either vocal or instrumental, the structure of a musical piece or to the process of creating or writing a new piece of music. People who create new compositions are called composers. Composers of primarily songs are usually called songwriters; with songs, the person who writes lyrics for a song is the lyricist. In many cultures, including Western classical music, the act of composing typically includes the creation of music notation, such as a sheet music "score", which is then performed by the composer or by other musicians. In popular music and traditional music, songwriting may involve the creation of a basic outline of the song, called the lead sheet, which sets out the melody, lyrics and chord progression. In classical music, orchestration (choosing the instruments of a large music ensemble such as an orchestra which will play the different parts of music, such as the melody, accompaniment, countermelody, bassline and so on) is typically done by the composer, but in musical theatre and in pop music, songwriters may hire an arranger to do the orchestration. In some cases, a pop or traditional songwriter may not use written notation at all and instead compose the song in their mind and then play, sing or record it from memory. In jazz and popular music, notable sound recordings by influential performers are given the weight that written or printed scores play in classical music.

Although a musical composition often uses musical notation and has a single author, this is not always the case. A work of music can have multiple composers, which often occurs in popular music when all members of a band collaborate to write a song or in musical theatre, when one person writes the melodies, a second person writes the lyrics and a third person orchestrates the songs.

Art music (alternatively called classical music, cultivated music, serious music, and canonic music) is music considered to be of high phonoaesthetic value. It typically implies advanced structural and theoretical considerations or a written musical tradition. In this context, the terms "serious" or "cultivated" are frequently used to present a contrast with ordinary, everyday music (i.e. popular and folk music, also called "vernacular music"). Many cultures have art music traditions; in the Western world, the term typically refers to Western classical music.

Folk music is a music genre that includes traditional folk music and the contemporary genre that evolved from the former during the 20th-century folk revival. Some types of folk music may be called world music. Traditional folk music has been defined in several ways: as music transmitted orally, music with unknown composers, music that is played on traditional instruments, music about cultural or national identity, music that changes between generations (folk process), music associated with a people's folklore, or music performed by custom over a long period of time. It has been contrasted with commercial and classical styles. The term originated in the 19th century, but folk music extends beyond that.

Starting in the mid-20th century, a new form of popular folk music evolved from traditional folk music. This process and period is called the (second) folk revival and reached a zenith in the 1960s. This form of music is sometimes called contemporary folk music or folk revival music to distinguish it from earlier folk forms. Smaller, similar revivals have occurred elsewhere in the world at other times, but the term folk music has typically not been applied to the new music created during those revivals. This type of folk music also includes fusion genres such as folk rock, folk metal, and others. While contemporary folk music is a genre generally distinct from traditional folk music, in U.S. English it shares the same name, and it often shares the same performers and venues as traditional folk music.

Singing is the art of creating music with the voice. It is the oldest form of musical expression, and the human voice can be considered the first musical instrument by some. The definition of singing varies across sources. Some sources define singing as the act of creating musical sounds with the voice. Other common definitions include "the utterance of words or sounds in tuneful succession" or "the production of musical tones by means of the human voice".

A person whose profession (or hobby) is singing is called a singer or a vocalist (in jazz or popular music). Singers perform music (arias, recitatives, songs, etc.) that can be sung with or without accompaniment by musical instruments. Singing is often done in an ensemble of musicians, such as a choir. Singers may perform as soloists or accompanied by anything from a single instrument (as in art songs or some jazz styles) up to a symphony orchestra or big band. Many styles of singing exist throughout the world.

Hip-hop (also known as rap music or simply rap) is a genre of popular music that emerged in the early 1970s alongside an associated subculture in the African-American and Latino communities of New York City. The musical style is characterized by the synthesis of a wide range of techniques, but rapping is frequent enough that it has become a defining characteristic. Other key markers of the genre are the disc jockey (DJ), turntablism, scratching, beatboxing, and instrumental tracks. Cultural interchange has always been central to the hip-hop genre; it simultaneously borrows from its social environment while commenting on it.

The hip-hop genre and culture emerged from block parties in ethnic minority neighborhoods of New York City, particularly the Bronx. DJs began expanding the instrumental breaks of popular records when they noticed how excited it would make the crowds. The extended breaks provided a platform for break dancers and rappers. These breakbeats enabled the subsequent evolution of the hip-hop style. Many of the records used were disco due to its popularity at the time. This disco-inflected music was originally known as disco-rap and later described as "old-school hip-hop".

In a musical composition, a chord progression or harmonic progression (informally chord changes, used as a plural, or simply changes) is a succession of chords. Chord progressions are the foundation of harmony in Western musical tradition from the common practice era of classical music to the 21st century. Chord progressions are the foundation of popular music styles (e.g., pop music, rock music), traditional music, as well as genres such as blues and jazz. In these genres, chord progressions are the defining feature on which melody and rhythm are built.

In tonal music, chord progressions have the function of either establishing or otherwise contradicting a tonality, the technical name for what is commonly understood as the "key" of a song or piece. Chord progressions, such as the extremely common chord progression I-V-vi-IV, are usually expressed by Roman numerals in classical music theory. In many styles of popular and traditional music, chord progressions are expressed using the name and "quality" of the chords. For example, the previously mentioned chord progression, in the key of E♭ major, would be written as E♭ major–B♭ major–C minor–A♭ major in a fake book or lead sheet. In the first chord, E♭ major, the "E♭" indicates that the chord is built on the root note "E♭" and the word "major" indicates that a major chord is built on this "E♭" note.

Jazz is a music genre that originated in the African-American communities of New Orleans, Louisiana, in the late 19th and early 20th centuries. Its roots are in blues, ragtime, European harmony, African rhythmic rituals, spirituals, hymns, marches, vaudeville song, and dance music. Since the 1920s Jazz Age, it has been recognized as a major form of musical expression in traditional and popular music. Jazz is characterized by swing and blue notes, complex chords, call and response vocals, polyrhythms and improvisation.

As jazz spread around the world, it drew on national, regional, and local musical cultures, which gave rise to different styles. New Orleans jazz began in the early 1910s, combining earlier brass band marches, French quadrilles, biguine, ragtime and blues with collective polyphonic improvisation. However, jazz did not begin as a single musical tradition in New Orleans or elsewhere. In the 1930s, arranged dance-oriented swing big bands, Kansas City jazz (a hard-swinging, bluesy, improvisational style), and gypsy jazz (a style that emphasized musette waltzes) were the prominent styles. Bebop emerged in the 1940s, shifting jazz from danceable popular music toward a more challenging "musician's music" which was played at faster tempos and used more chord-based improvisation. Cool jazz developed near the end of the 1940s, introducing calmer, smoother sounds and long, linear melodic lines.

A chord chart (or chart) is a form of musical notation that describes the basic harmonic and rhythmic information for a song or tune. It is the most common form of notation used by professional session musicians playing jazz or popular music. It is intended primarily for a rhythm section (usually consisting of piano, guitar, drums and bass). In these genres the musicians are expected to be able to improvise the individual notes used for the chords (the "voicing") and the appropriate ornamentation, counter melody or bassline.

In some chord charts, the harmony is given as a series of chord symbols above a traditional musical staff. The rhythmic information can be very specific and written using a form of traditional notation, sometimes called rhythmic notation, or it can be completely unspecified using slash notation, allowing the musician to fill the bar with chords or fills any way they see fit (called comping). In Nashville notation the key is left unspecified on the chart by substituting numbers for chord names. This facilitates on-the-spot key changes to songs. Chord charts may also include explicit parts written in modern music notation (such as a musical riff that the song is dependent on for character), lyrics or lyric fragments, and various other information to help the musician compose and play their part.

Classical music generally refers to the art music of the Western world, considered to be distinct from Western folk music or popular music traditions. It is sometimes distinguished as Western classical music, as the term "classical music" can also be applied to non-Western art musics. Classical music is often characterized by formality and complexity in its musical form and harmonic organization, particularly with the use of polyphony. Since at least the ninth century, it has been primarily a written tradition, spawning a sophisticated notational system, as well as accompanying literature in analytical, critical, historiographical, musicological and philosophical practices.

Rooted in the patronage of churches and royal courts in Europe, surviving early medieval music is chiefly religious, monophonic and vocal, with the music of ancient Greece and Rome influencing its thought and theory. The earliest extant music manuscripts date from the Carolingian Empire (800–887), around the time which Western plainchant gradually unified into what is termed Gregorian chant. Musical centers existed at the Abbey of Saint Gall, the Abbey of Saint Martial and Saint Emmeram's Abbey, while the 11th century saw the development of staff notation and increasing output from medieval music theorists. By the mid-12th century, France became the major European musical center: the religious Notre-Dame school first fully explored organized rhythms and polyphony, while secular music flourished with the troubadour and trouvère traditions led by poet-musician nobles. This culminated in the court-sponsored French ars nova and Italian Trecento, which evolved into ars subtilior, a stylistic movement of extreme rhythmic diversity. Beginning in the early 15th century, Renaissance composers of the influential Franco-Flemish School built on the harmonic principles in the English contenance angloise, bringing choral music to new standards, particularly the mass and motet. Northern Italy soon emerged as the central musical region, where the Roman School engaged in highly sophisticated methods of polyphony in genres such as the madrigal, which inspired the brief English Madrigal School.

A musical ensemble, also known as a music group, musical group, or a band is a group of people who perform instrumental and/or vocal music, with the ensemble typically known by a distinct name. Some music ensembles consist solely of instrumentalists, such as the jazz quartet or the orchestra. Other music ensembles consist solely of singers, such as choirs and doo-wop groups. In both popular music and classical music, there are ensembles in which both instrumentalists and singers perform, such as the rock band or the Baroque chamber group for basso continuo (harpsichord and cello) and one or more singers. In classical music, trios or quartets either blend the sounds of musical instrument families (such as piano, strings, and wind instruments) or group instruments from the same instrument family, such as string ensembles (e.g., string quartet) or wind ensembles (e.g., wind quintet). Some ensembles blend the sounds of a variety of instrument families, such as the orchestra, which uses a string section, brass instruments, woodwinds, and percussion instruments, or the concert band, which uses brass, woodwinds, and percussion. In jazz ensembles or combos, the instruments typically include wind instruments (one or more saxophones, trumpets, etc.), one or two chordal "comping" instruments (electric guitar, acoustic guitar, piano, or Hammond organ), a bass instrument (bass guitar or double bass), and a drummer or percussionist. Jazz ensembles may be solely instrumental, or they may consist of a group of instruments accompanying one or more singers. In rock and pop ensembles, usually called rock bands or pop bands, there are usually guitars and keyboards (piano, electric piano, Hammond organ, synthesizer, etc.), one or more singers, and a rhythm section made up of a bass guitar and drum kit.

Music ensembles typically have a leader. In jazz bands, rock and pop groups, and similar ensembles, this is the band leader. In classical music, orchestras, concert bands, and choirs are led by a conductor. In orchestra, the concertmaster (principal first violin player) is the instrumentalist leader of the orchestra. In orchestras, the individual sections also have leaders, typically called the "principal" of the section (e.g., the leader of the viola section is called the "principal viola"). Conductors are also used in jazz big bands and in some very large rock or pop ensembles (e.g., a rock concert that includes a string section, a horn section, and a choir that accompanies a rock band's performance).

Accompaniment is the musical part which provides the rhythmic and/or harmonic support for the melody or main themes of a song or instrumental piece. There are many different styles and types of accompaniment in different genres and styles of music. In homophonic music, the main accompaniment approach used in popular music, a clear vocal melody is supported by subordinate chords. In popular music and traditional music, the accompaniment parts typically provide the "beat" for the music and outline the chord progression of the song or instrumental piece.

The accompaniment for a vocal melody or instrumental solo can be played by a single musician playing an instrument such as piano, pipe organ, or guitar. While any instrument can in theory be used as an accompaniment instrument, keyboard and guitar-family instruments tend to be used if there is only a single instrument, as these instruments can play chords and basslines simultaneously (chords and a bassline are easier to play simultaneously on keyboard instruments, but a fingerpicking guitarist can play chords and a bassline simultaneously on guitar). A solo singer can accompany themself by playing guitar or piano while they sing, and in some rare cases, a solo singer can even accompany themself just using their voice and body (e.g., Bobby McFerrin).

Pop music, or simply pop, is a genre of popular music that originated in its modern form during the mid-1950s in the United States and the United Kingdom. During the 1950s and 1960s, pop music encompassed rock and roll and the youth-oriented styles it influenced. Rock and pop music remained roughly synonymous until the late 1960s, after which pop became associated with music that was more commercial, ephemeral, and accessible.

Identifying factors of pop music usually include repeated choruses and hooks, short to medium-length songs written in a basic format (often the verse–chorus structure), and rhythms or tempos that can be easily danced to. Much of pop music also borrows elements from other styles such as rock, hip hop, urban, dance, Latin, and country.

Vaudeville (/ˈvɔːd(ə)vɪl, ˈvoʊ-/; French: [vodvil] ) is a theatrical genre of variety entertainment which became popular in the United States and Canada from the early 1870s until the early 1930s.

In some ways analogous to music hall from Victorian Britain, a typical North American vaudeville performance was made up of a series of separate, unrelated acts grouped together on a common bill. Types of acts have included popular and classical musicians, singers, dancers, comedians, trained animals, magicians, ventriloquists, strongmen, female and male impersonators, acrobats, clowns, mimes, illustrated songs, jugglers, athletes, lecturing celebrities, or scenes from plays, one-act plays, minstrels, and films. A vaudeville performer is often referred to as a "vaudevillian."