A hook is a musical idea, often a short riff, passage, or phrase, that is used in popular music to make a song appealing and to "catch the ear of the listener". The term generally applies to popular music, especially rock music, R&B, hip hop, dance music, and pop. In these genres, the hook is often found in, or consists of, the chorus. A hook can be either melodic or rhythmic, and often incorporates the main motif for a piece of music. For example, the melody to the lyric "And I will always love you" in the song "I Will Always Love You" over the I-vi-IV-V progression.
One definition of a hook is "a musical or lyrical phrase that stands out and is easily remembered". Definitions typically include some of the following: that a hook is repetitive, attention-grabbing, memorable, easy to dance to, and has commercial potential and lyrics. A hook has been defined as a "part of a song, sometimes the title or key lyric line, that keeps recurring". Alternatively, the term has been defined as
the foundation of commercial songwriting, particularly hit-single writing", which varies in length from the repetition of "one note or a series of notes...[to] a lyric phrase, full lines, or an entire verse. The hook is 'what you're selling'. Though a hook can be something as insubstantial as a 'sound' (such as da doo ron ron), "ideally should contain one or more of the following: (a) a driving, danceable rhythm; (b) a melody that stays in people's minds; (c) a lyric that furthers the dramatic action, or defines a person or place.
While some melodic hooks include skips of a eighths or more to make the line more interesting, a hook can be equally catchy by employing rhythmic syncopation or other devices. A hook may also garner attention from listeners from other factors, such as the vocal timbre or instrumentation, as in the case of the Beach Boys' use of an unusual theremin-like instrument in "Good Vibrations". Some hooks become popular without using any unusual elements. For example, in the song "Be My Baby", performed by The Ronettes, the hook consists of the words "be my baby" over the conventional I-vi-IV-V chord progression of the chorus. Hooks in hip hop almost always refer to the chorus between verses.
Use in market research 
The hooks of songs may be used in market research to assist in gauging the popularity of a song by the recognizability of its hook. Often radio stations conduct "call out" either on the Internet, via telephone, or a music test (either online or in an in-person setting) to conduct surveys. Stations may use the services of a professional "hook service" or prepare the materials themselves. Hooks used are typically seven to ten seconds long. Some groups release these research hooks on a single's CD release.
See also 
- Covach, John (2005). "Form in Rock Music: A Primer". In Stein, Deborah. Engaging Music: Essays in Music Analysis. New York: Oxford University Press. p. 71. ISBN 0-19-517010-5.
- Monaco and Riordan (1980, p. 178). Cited in Burns, Gary (1987). "A Typology of 'Hooks' in Popular Records", Popular Music, Vol. 6, No. 1. (Jan., 1987), pp. 1-20
- Hurst and Delson 1980, p.58. Cited in Burns, Gary (1987) "A Typology of 'Hooks' in Popular Records", Popular Music, Vol. 6, No. 1. (Jan., 1987), pp. 1-20.
- Kasha and Hirschhorn (1979), p.28-29. Cited in Gary Burns (January 1987). "A Typology of "Hooks" in Popular Records". Popular Music 6 (1): 1–20. doi:10.1017/S0261143000006577. JSTOR 853162.