Chord Progressions & Cadences

Music Theory Fundamentals

Chapter 8 · Chord Progressions & Cadences

Chapter 7 gave every chord in a key its own Roman numeral. This chapter covers how those chords actually move — the recurring patterns that give music its sense of direction, and the specific real endings, called cadences, that punctuate a musical phrase the way a period or a question mark punctuates a sentence.

Cadences: Punctuation for Harmony

A cadence is a real, specific two-chord (or more) pattern that closes a musical phrase — and different cadences close it with genuinely different degrees of finality.

Cadence	Motion	Real character
Authentic	V → I	Full closure (perfect: both chords root-position, tonic on top; imperfect: a weaker variant)
Plagal	IV → I	The real "Amen cadence" — named for its frequent setting to the word "Amen" in hymns
Half	Any chord → V	Sounds genuinely incomplete, demanding continuation
Deceptive	V → vi (instead of I)	A real "interrupted" resolution — expectation deliberately thwarted

A real, honest scholarly dispute

Not every real theorist agrees the plagal cadence deserves full "cadence" status at all. Music theorist William Caplin has real, documented arguments that true plagal cadences didn't actually function this way in classical-era music — he contends the IV→I motion "cannot confirm a tonality" on its own, and more often functions as a prolongation of an already-established tonic rather than a genuine, independent close. Worth knowing the field isn't fully settled on this one.

Common Chord Progressions

Beyond single cadences, whole progressions recur constantly across genres — patterns of movement, not just endings.

The ii-V-I progression

Real, documented as jazz harmony's own single most central progression — typically voiced ii^m7–V⁷–I^maj7 — prized for the genuinely smooth voice-leading it offers between the thirds and sevenths of each chord. It shows up far beyond jazz too, as a real staple of virtually every style of Western popular music, with documented examples running from "Honeysuckle Rose" (1928) through The Beatles' "If I Fell."

The "50s progression" (I-vi-IV-V) and its relative, I-V-vi-IV

Also real, documented under the names "Heart and Soul" changes, the "Stand by Me" changes, and the doo-wop progression. Despite the "50s" name, real documented examples of this progression predate the 1950s by centuries, appearing in 17th-century works by Dieterich Buxtehude and J.S. Bach. Its own real, later ubiquity in popular music — hundreds of documented recordings from "Earth Angel" (1954) onward, across rock, pop, and indie — is exactly what made it the target of the widely-known 2009 "Four Chords" comedy medley by the group Axis of Awesome, which strung together dozens of real hit songs built on the same four chords back to back.

Hands-On Exercises

Exercise 1

Using Chapter 7's own C major diatonic chords, write out the actual chord names (not just Roman numerals) for a I-IV-V-I progression in C major.

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Exercise 2

A phrase ends with a G major chord moving to an A minor chord, in the key of C major. Using this chapter's own cadence table and Chapter 7's own Roman numerals, identify which cadence type this is.

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Exercise 3

Explain, in your own words, why a half cadence (ending on V) sounds "incomplete" to a listener while a perfect authentic cadence (V-I, both root position) sounds fully resolved — referring to Chapter 7's own real scale-degree names where useful.

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Chapter 8 Quick Reference

Authentic cadence (V→I) — full closure; plagal (IV→I) — the "Amen cadence," with real, disputed status as a true cadence (Caplin)
Half cadence — ends on V, sounds incomplete; deceptive cadence — V resolves to vi instead of I
ii-V-I — jazz harmony's own central progression, also a real staple across popular music generally
The "50s progression" (I-vi-IV-V) — real documented use predating the 1950s (Buxtehude, Bach), later the target of the "Four Chords" comedy medley
Next chapter: Musical Form — Binary, Ternary, Sonata & Rondo