8.1.9: Harmony - Plagal Progressions
The IV chord, while certainly an extremely frequent predominant/subdominant chord in common-practice repertoire, has an even more prominent place in pop/rock music. Perhaps borne out of the 5-6 neighboring motion found in shuffle-blues guitar accompaniment patterns, an alternation between I and IV is a common occurrence in numerous genres.
In “Soul Man” by Sam and Dave, the chord progression used in the verse consists of an alternation of I and IV (listen carefully to the bass).
A similar oscillation between I and IV can be found in the verse to “In the Midnight Hour” by Wilson Pickett.
This kind of chord progression isn’t limited to Soul and R&B, of course. The beginning of “After The Gold Rush” by Neil Young features a similar progression (it deviates after the the words “…drummers drummin…” Also, note the discrepancy between the melody notes and the chords throughout).
Double-plagal progression
The “double-plagal” progression ( Walter Everett’s term ) is an expansion of the plagal progression discussed above to include the “IV/IV” chord prior to the IV chord. This is perhaps more simply explained as bVII-IV-I (or simply VII-iv-I in minor). The most famous instance of the double-plagal progression is likely the coda from “Hey Jude” by The Beatles, performed here by Wilson Pickett:
Extended plagal progressions
The “applied IV” chord can be used in sequence, similar to the descending-fifths progression in common-practice music. In the version of “Hey Joe” by Jimi Hendrix, the verse consists of three iterations of the plagal motion in a descending-fourths pattern, which results in the progression: bVI-bIII-bVII-IV-I, in the key of E major.