Hook (music)

A riff is a repeated chord progression or refrain in music ; it is a pattern, or melody, often played by the rhythm section instruments or solo instrument, that forms the basis or accompaniment of a musical composition. Though riffs are most often found in rock music, heavy metal music, Latin, funk, and jazz, classical music is also sometimes based on a riff, such as 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.

Popular music is music with wide appeal that is typically distributed to large audiences through the music industry. These forms and styles can be enjoyed and performed by people with little or no musical training. It stands in contrast to both art music and traditional or "folk" music. Art music was historically disseminated through the performances of written music, although since the beginning of the recording industry, it is also disseminated through recordings. Traditional music forms such as early blues songs or hymns were passed along orally, or to smaller, local audiences.

Rock music is a broad genre of popular music that originated as "rock and roll" in the United States in the late 1940s and early 1950s, developing into a range of different styles in the mid-1960s and later, particularly in the United States and United Kingdom. It has its roots in 1940s and 1950s rock and roll, a style that drew directly from the blues and rhythm and blues genres of African-American music and from country music. Rock also drew strongly from a number of other genres such as electric blues and folk, and incorporated influences from jazz, classical, and other musical styles. For instrumentation, rock has centered on the electric guitar, usually as part of a rock group with electric bass guitar, drums, and one or more singers. Usually, rock is song-based music with a 44 time signature using a verse–chorus form, but the genre has become extremely diverse. Like pop music, lyrics often stress romantic love but also address a wide variety of other themes that are frequently social or political. Rock was the most popular genre of music in the United States and much of the Western world from the 1950s to the 2010s.

Contemporary R&B is a popular music genre that combines rhythm and blues with elements of pop, soul, funk, hip hop, and electronic music.

Hip hop music or hip-hop music, also known as rap music and formerly known as disco rap, is a genre of popular music that originated in New York City in the 1970s. It consists of stylized rhythmic music that commonly accompanies rapping, a rhythmic and rhyming speech that is chanted. It developed as part of hip hop culture, a subculture defined by four key stylistic elements: MCing/rapping, DJing/scratching with turntables, break dancing, and graffiti writing. Other elements include sampling beats or bass lines from records, and rhythmic beatboxing. While often used to refer solely to rapping, "hip hop" more properly denotes the practice of the entire subculture. The term hip hop music is sometimes used synonymously with the term rap music, though rapping is not a required component of hip hop music; the genre may also incorporate other elements of hip hop culture, including DJing, turntablism, scratching, beatboxing, and instrumental tracks.

Electronic dance music (EDM), also known as dance music, club music, or simply dance, is a broad range of percussive electronic music genres made largely for nightclubs, raves, and festivals. It is generally produced for playback by DJs who create seamless selections of tracks, called a DJ mix, by segueing from one recording to another. EDM producers also perform their music live in a concert or festival setting in what is sometimes called a live PA.

Pop music is a genre of popular music that originated in its modern form during the mid-1950s in the United States and the United Kingdom. The terms popular music and pop music are often used interchangeably, although the former describes all music that is popular and includes many disparate styles. 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.

Rhythm generally means a "movement marked by the regulated succession of strong and weak elements, or of opposite or different conditions". This general meaning of regular recurrence or pattern in time can apply to a wide variety of cyclical natural phenomena having a periodicity or frequency of anything from microseconds to several seconds ; to several minutes or hours, or, at the most extreme, even over many years.