Popular records often include accidents, indicating something about the flexibility of musical practices and the limits of theories. Musical hooks provide useful test-cases because they are normally considered the least accidental part of a song.
One imagines the hook emerging fully formed in a moment of inspiration—the catchy phrase that comes into a songwriter’s head—or at least of calculation: But hooks sometimes incorporate accidents or happen accidentally. If hooks are less than completely determinate, then every aspect of a popular record must be subject to contingency.
This according to “Accidents, hooks, and theory” by Charles Kronengold (Popular music XXIV/3 [October 2005] pp. 381–397).
Above and below, Pérez Prado’s Cherry pink and apple blossom white, one of the examples cited in the article. The intended hook was the prominent trumpet lip slurs; the accidental hook, which made the record a number one U.S. hit in 1955, was Prado’s occasional interpolated vocalizations.