Harmony in pop/rock music does not always follow the same norms and patterns of classical-era music. Thus, functional-bass notation does not work for all situations. Instead, we will primarily use Roman numerals for our analysis of harmony in pop/rock music, occasionally using functional bass as a supplement to help us make sense of a particular harmonic pattern or relate it to what we’ve studied in classical harmony.
One key difference between rock and classical harmony is that chords in pop/rock music are almost always root-position triads or seventh chords. This affects the “rules” of harmonic syntax, as 6/3 chords in classical progressions are replaced by 5/3 chords in pop/rock progressions. (For instance, the classical progression IV–IV6 becomes IV–VI. The same bass line does the same work, but by using a 5/3 chord instead of a 6/3 chord, the functional progression changes to something that would “break the rules” of classical syntax.) This can make harmonic analysis a little tricky in pop/rock music, especially since there is no published theory of rock harmony that is equal to Quinn’s functional theory of classical harmony. However, it makes chord labeling and harmonic dictation simpler. Most of the time, all you need is the scale degree of the bass.
Following is a chart of bass scale degrees and the roots/Roman numerals most typically associated with them. Keep this chart handy when transcribing and dictating rock harmonic progressions. As you can see, most bass notes typically go with a single chord.
Bass scale degrees and commonly associated harmonies in pop/rock music. Less common chords are enclosed in square brackets.
Harmonic functions in minor
Harmonic functions in minor keys of pop/rock songs, particularly in the last couple decades, tend to deviate from classical syntax in different ways than major-key songs. See the Harmonic functions in minor resource for more details about this.
There are a number of common stock chord progressions that recur in many pop/rock songs. Typically, these stock progressions, or schemata, will occur in cyclical patterns; that is, the same progression will repeat multiple times in a row. This is particularly common in choruses of verse-chorus songs, but also happens in verses, strophes, and bridges. This is helpful for identifying harmonies by ear, since in addition to listening for bass scale degrees and considering whether the harmonies are chords of the fifth (5/3 or 7) or chords of the sixth (typically 6/3 or 6/5), we can listen for common patterns that we’ve heard in other songs. Following are a number of common schemata for pop/rock harmonic progressions.
||: I – VI – IV – V :||
||: I – VI – II – V :||
||: VI – IV – I – V :|| (in major)
||: I – VI – III – VII :|| (in minor)
||: I – V – VI – IV :|| (“With or Without You” variant)
||: IV – I – V – VI :|| (“deceptive” variant)
I – III – IV . . . (to begin a phrase)
||: I - - - | IV - I - | V IV I - :|| (12-bar blues)
||: I - - - | I - - - | IV - I - | V IV I -:|| (16-bar blues)
||: I – V – VI – III – IV – I – IV – V :||
||: I – V6 – VI – III6 – IV – I6 – IV – V :|| (stepwise bass version)
I – V – VI – III . . . (to begin a phrase; “truncated” version)
||: I – VII – VI – V :||
||: I – IV – VII – III :||
||: I - IV :||
||: I - bVII - IV - I :||
||: bVI - bIII - bVII - IV - I :||
Rock’s “tonal systems”
Walter Everett has posited six tonal systems to which most pop/rock songs belong. The following sections summarize four of these with examples (all but 1 and 6—the most and least tonal). See Everett’s 2004 article in Music Theory Online for a more detailed exploration of these “systems.”
System 1: Pop/rock tonality that strongly resembles common-practice classical tonality (major and minor keys, with parallel-key borrowing).
System 2: Pop/rock tonality that draws on diatonic modes (such as Dorian, Mixolydian, Aeolian).
System 6: Chromatically inflected minor-pentatonic-based pop/rock tonality.