Form in pop/rock music – Formal functions

Functions for Primary Modules

Strophe (A)

The primary function of a strophe module is “to present the primary lyric and musical content and to provide a point at which the song might satisfyingly end” (Summach, p. 58).

In strophic form (AAA), strophes are the only core modules, and thus do not participate in a functional progression. Functional progression takes place on the phrase level within the strophe. The strophe modules themselves tend to set a stanza of text each with music that is self-contained and harmonically closed.

See Carl Perkins’s “Blue Suede Shoes” for strophe examples.

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  • 0:00 – Strophe 1
  • 0:19 – Strophe 2
  • 0:41 – Instrumental strophe
  • 0:58 – Strophe 3
  • 1:21 – Instrumental strophe
  • 1:37 – Strophe 1 (slightly varied repetition)
  • 1:54 – Strophe 4

In 32-bar form (AABA), the strophe’s function as holding the primary text and music, and its function as being a stable point of departure and return, are elevated through contrast with the bridge module. In AABA songs, strophe function often involves the prolongation of tonic harmony. Strophes tend to be longer in strophic songs than in AABA songs. In both forms, srdc is by far the most common internal pattern for strophes. For three-part strophes, the 12-bar blues progression is the most common pattern.

Frank Sinatra’s “Strangers in the Night” is in AABA form. Its first two strophes begin at 0:10 and 0:31.

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Chorus (C)

Chorus modules are lyric-invariant and contain the primary lyrical material of the song. Chorus function is also typified by heightened musical intensity relative to the verse, including features like “a more dense or active instrumental texture; prominent background vocals; and/or a higher register melody” (Summach, p. 106). Choruses most frequently (but not exclusively) begin on-tonic.

Chorus modules are distinct from refrains primarily by virtue of their being modules in and of themselves, where refrains are contained within a module.

An example chorus can be found at 1:34 in Bon Jovi’s “Livin’ on a Prayer.”

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Functions for Secondary Modules

Bridge (B)

Bridge function shares many traits with the continuation function of classical form. Bridge modules tend to play a transitional role (neither the point from which to depart, nor the point of arrival) in the formal cycle, generating high expectation for the return of the primary module (A or C) by contrasting with it and temporarily withholding it. A bridge module “must be followed by [the primary module] in order for its function to be satisfied” (Summach, p. 79), though it is possible for a bridge module in VC form to lead into a final verse module or even a mid-song introduction (see U2’s “Pride (In the Name of Love)”). Bridge modules tend to emphasize non-tonic harmonies and commonly end on dominant harmony.

In VC songs, bridge modules are more free to contrast verse and chorus modules without a strong need to build expectation for the return of the chorus than in AABA form. In an AABA song, building expectation for the return of the strophe and arriving on dominant harmony in preparation of that return are essential to bridge function.

See “Strangers in the Night” (audio above) or the Beatles’ “I Want to Hold Your Hand” for examples of bridges in AABA form.

“Come On Eileen” by Dexy’s Midnight Runners contains an example of a bridge module in a verse-chorus song at 2:55. It finishes with a climb borrowed from the verses at 2:55, and sets up a chorus arrival at 3:34.

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Verse (V)

Verse modules are lyric-variant and often contain lyrics thatadvance the narrative. Until the 1960s, verse modules tended to be harmonically closed. Beginning in the 1960s, verse modules became more and more likely to be harmonically open (Summach, p. 114). Verses (like strophes) tend to begin on-tonic.

The first and second verses to “Livin’ on a Prayer” (audio above) begin at 0:44 and 1:52, respectively.

Prechorus (P)

Prechorus function is most significantly typified in energy gain. Prechorus modules originate historically in the d (departure) section of an srdc pattern. (Think of an srdc strophe becoming longer until sr forms its own two-part verse module (or two successive verse modules), d forms its own prechorus module, and c forms its own chorus module.) As a result, prechorus modules bear many of the functional characteristics of d—fragmentation, acceleration of harmonic rhythm, and movement away from tonic harmony—and harmonic openness.

The first prechorus module to “Livin’ on a Prayer” (audio above) begins at 1:15.

Postchorus (Z)

A short module that follows a chorus and serves only to close the cycle (not to introduce or transition to the beginning of the next cycle) has postchorus function (Mark Spicer 2011, par. 9).

The second cycle of “Livin’ on a Prayer” (audio above) ends with a brief, two-bar postchorus at 2:54.

Functions for Auxiliary Modules

Introduction & mid-song introduction (I)

Introductions tend to be short and untexted (i.e., instrumental) and tend to present musical material from one or more core modules to come. Introduction modules transition from the unmetered silence that precede the song to the musical activity of the first core module. This is often accomplished by the introduction of musical material in layers (e.g., one instrument at a time) or a more generic building of energy. Occasionally intros include non-core material. Such intros often correspond to an outro based on the same material, and together they create a “bookend” effect.

It is also possible to have multiple intro modules in a row, with each based on different music. Such a succession of intros would be labeled I1, I2, etc. Dexy’s Midnight Runners’ “Come On Eileen” (audio above) contains several different intro modules with different musical content.

Mid-song intros function similarly, but in the middle of the song. They usually introduce the first module in the formal cycle. “Livin’ on a Prayer” has a brief mid-song introduction at 1:48, which sets up the arrival of the second cycle (beginning with Verse 2). A more extended mid-song introduction comes at 1:57 of “Pride (In the Name of Love)” by U2, which sets up the verse that begins the final cycle.

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Outro (O)

Outros function as a transition from song back to silence, and thus decrease energy. Often this is accomplished in the recording studio by way of a fadeout. When an outro module is present, it is almost always based on material from the last core module that preceded it. Non-core outros tend to draw material from a non-core intro (the above “bookend” effect). “Rock songs almost always end with material that has been heard earlier in the song: either a core module, a core-based auxiliary module, or a reprise of the introduction” (Summach, p. 47). Outros exhibit closing rhetoric (see below).

(See below for an example.)

Coda (X)

A coda is a “song-ending module that presents new material” (Summach, p. 47)—in other words, an outro not based on music previously heard. Like outros, codas exhibit closing rhetoric (see below).

Muse’s “Resistance” has both a coda and an outro. The coda, which contains new musical and narrative material, begins at 4:05, following the final chorus. This new module, which brings something of a conclusion (if an open-ended one) to the narrative, gives way to a song-ending outro at 4:54. Aside from the clear change in content and texture at 4:54, what makes this a clear change from coda to outro is the return of material from the introduction, creating the “bookend” effect that is common from intros and outros working together.

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Closing rhetoric

Closing rhetoric involves common patterns and techniques that signal that the end of the song is likely coming soon. Typical patterns and techniques include immediate repetition of a core module (except for the first core module) or part of a core module, thinning out of the texture, late-song intensification, fadeout, and bringing a previously harmonically open module to a point of harmonic closure. Closing rhetoric is typically found in outros, codas, and the last core module of a song (A or C).

Functions for Standout Passages Within Modules


“A lyric-invariant passage within a module that is otherwise lyric-variant” (Summach, p. 322). Like a climb (below), a refrain is too short to form its own module—typically a phrase or less. A refrain is most often the last line or so of a module’s text (tail refrain), and occasionally the material at the beginning of a module’s text (head refrain).

“Cathedrals” by Jump Little Children contains a head refrain. Each strophe begins with the same line, “In the shadows of tall buildings…”

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“Blue Suede Shoes” (audio above) and “I Want to Hold Your Hand” both contain tail refrains at the ends of their strophes, emphasizing the title lyrics.


“A phrase with prechorus function, but of insufficient length to detach from the verse as a separate module” (Summach, p. 321). Always the last phrase of a verse module.

“Come On Eileen” (audio above) contains a one-phrase climb at the end of its verses and bridge (“Tu-ra-lu-ra…”).

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