VII. Popular Music

Bryn Hughes and Megan Lavengood

Key Takeaways

Sections in pop/rock music typically consist of two, three, or four phrases. These phrases are usually organized as follows:

  • Two-part: aa′
  • Three-part: aa′b (often a 12-bar blues)
  • Four-part: (statement, restatement/response, departure, conclusion)

This chapter discusses the structure of song sections such as a verse, chorus, or bridge. Each section consists of at least two phrases—in pop/rock music, a phrase is a musical unit that typically lasts for four bars and corresponds to one line of the lyrics. In labeling these structures, phrases are designated by lowercase letters.


A section is two-part when the phrases that make up the section can be grouped into a first half and a second half. In two-part sections, the second half is usually based on the same music as the first half, and thus it is labeled aa’. Often these two halves begin the same but have different endings, participating in an (weak → strong) relationship.

The chorus to “Livin’ on a Prayer” (1’33”) has an aa′ structure (Example 1). The first four-bar phrase (“Oh, we’re half-way there…”) and the second four-bar phrase (“Take my hand…”) have identical melody and harmony (so they both get the letter a), but different lyrics (so the second a is marked as “a prime”: a′). Note that in many songs, this relationship is not as clear cut. However, if the two phrases begin with similar musical material, give them the same letter. New lyrics, new musical endings, or musical variations simply warrant a “prime.”

Very rarely, a section’s phrases can be grouped into two clear halves based on different music. Such a section is labeled ab.

[table id=27 /]

Example 1. “Livin’ on a Prayer.”


A section containing three phrases is a three-part section. If the first two phrases are based on the same music and the third is different, the section is labeled aa′b.

12-bar blues progressions are the most common example of a three-part aa’b section. “Hound Dog”  contains aa′b strophes (Example 2).

[table id=28 /]

Example 2. “Hound Dog.”


A section composed of four phrases often contains a sentential structure (presentation → continuation → cadential/conclusion). In pop/rock music, this often appears as a basic musical idea in the first phrase, a repetition or “response” to it in the second, contrasting material in the third phrase (often employing fragmentation, acceleration of harmonic rhythm, and movement away from tonic harmony), and a conclusion in the fourth phrase―either with a return to the basic idea and tonic harmony or with still newer material that forms a strong melodic, rhythmic, and harmonic conclusion. Walter Everett (2001, 132) has called such a four-phrase sentential structure in pop/rock music (statement, restatement/response, departure, conclusion).

In conventional lettering, an srdc section could employ an aaba structure (with statement material returning as a restatement and again as the conclusion), or an aabc structure (where the conclusion material is new). Occasionally abcd or abca are possible, but only if b is a clear response to a, not simply new material.

An srdc structure tends to tend to divide neatly into halves: sr and dc.

Bobby Darin’s “Dream Lover” (Example 3) provides a classic example of a four-part srdc phrase structure.

[table id=29 /]

Example 3. “Dream Lover.”

Further Reading
  • Everett, Walter. 2001. The Beatles as Musicians: The Quarry Men through Rubber Soul. New York: Oxford University Press.
  1. Worksheet on Section Structures (.pdf, .docx).



Icon for the Creative Commons Attribution-ShareAlike 4.0 International License

OPEN MUSIC THEORY by Bryn Hughes and Megan Lavengood is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License, except where otherwise noted.

Share This Book