# AI Wiki - Music - Cadences ## Overview A cadence is the harmonic punctuation at the end of a phrase: the last two chords that tell the ear "full stop", "comma" or "surprise". Melodies and lyrics breathe in phrases (often 4 or 8 bars), and the chords at each phrase end decide whether the music feels finished or must go on. There are four types every musician should recognise, defined by the last two chords in Roman numerals ([[AI Wiki - Music - Diatonic Chords and Roman Numerals]]): | Type (US) | British name | Chords | Feels like | |---|---|---|---| | Authentic | Perfect | V → I | Full stop | | Plagal | Plagal | IV → I | Soft "Amen" | | Half | Imperfect | anything → V | Comma, question | | Deceptive | Interrupted | V → vi (or anything but I) | Surprise, "not yet" | Watch the terminology: British "imperfect cadence" means a half cadence, while American "imperfect authentic cadence" is a weaker V-I. Same words, different things. ## Why V → I is so strong The dominant chord (V, or V7) contains the **leading tone**, degree 7 of the scale, a semitone below the tonic. In G major, D7 = D-F#-A-C: F# wants to rise a semitone to G, and C (the seventh) wants to fall a semitone to B, the third of G. Add the bass jumping from D down a fifth to G, and three forces push towards the tonic at once. That's the whole engine of tonal harmony, and the reason [[AI Wiki - Music - Common Chord Progressions]] keep returning to V before home. On piano, the voice leading is easy to see in C: G7 (B-D-F-G) to C (C-E-G). B moves up to C, F moves down to E, G stays. ```chord orientation: horizontal --- symbol: G7 pitches: B3 D4 F4 G4 title: G7 (V7) --- symbol: C pitches: C4 E4 G4 title: C (I) ``` ## Authentic cadence (V → I) The strongest, most final cadence: dominant to tonic. Practically every tonal piece ends on one. - **Perfect authentic cadence (PAC):** both chords in root position, and the tonic note in the top voice of the final chord. The most conclusive ending possible. - **Imperfect authentic cadence (IAC):** still V → I, but weaker: the melody ends on the 3rd or 5th of the chord, one of the chords is inverted, or vii° replaces V. For a guitarist [[AI Wiki - Music - Strumming Patterns|strumming]] [[AI Wiki - Music - Guitar Open Chords|open chords]], D → G (or D7 → G) in G, A → D in D and E → A in A are all authentic cadences. In minor keys, the V must be major to get the leading tone: E or E7 → Am, B7 → Em ([[AI Wiki - Music - Minor Scales]]). ```chord D7 xx0212 xx0213 --- G 320003 210003 --- B7 x21202 x21304 --- Em 022000 023000 ``` D7 → G (V7-I in G) and B7 → Em (V7-i in E minor): two authentic cadences in open position. Notice how B7's D# resolves up a semitone to the E on the D string. ## Plagal cadence (IV → I) Subdominant to tonic: the "Amen" sung at the end of hymns, which is why it's also called the Amen cadence. It's softer and warmer than V-I because there's no leading tone, just the tonic note held as a common tone (C is in both F and C). In pop and [[AI Wiki - Music - Rock Music|rock]] it often follows an authentic cadence as a coda, or ends a song with a gospel or anthemic feel. A darker variant borrows the minor iv: C → Fm → C, a "minor plagal" ending found in many ballads. On guitar in G: C → G. In D: G → D. In A: D → A. ## Half cadence (… → V) Any phrase that stops on the dominant: I → V, IV → V, ii → V. It sounds open, like a question or a comma, and is usually answered by a following phrase that ends with an authentic cadence (the "question and answer" or antecedent-consequent pair). Verses that end on V before the chorus are the everyday pop example: the D at the end of a G-major verse makes you lean into what comes next. In minor, a special form is the **Phrygian half cadence**, iv6 → V (in A minor: Dm/F → E), with the bass falling a semitone from F to E. It has an old, Spanish flavour, related to the end of the Andalusian cadence (Am-G-F-E). ## Deceptive cadence (V → vi) The ear expects V → I, and gets V → vi instead. In G: D → Em. In C: G → Am. The bass still rises a step (D to E) and the vi shares two notes with I (Em and G share G and B), so it sounds plausible but unfinished. Composers use it to extend a phrase, delay the ending, or add a touch of melancholy before the real final cadence. Other "deceptive" landings exist (V → IV, or V → ♭VI in rock: G → A♭ in C) but V → vi is by far the most common. ## All four in one chart A practice chart in G: each line is a four-bar phrase ending with one cadence type. ```chords {title: Four cadences in G} {key: G} {time: 4/4} {start_of_verse: Authentic (V-I)} [G]1 2 3 4 [C]1 2 3 4 [D7]1 2 3 4 [G]1 2 3 4 {end_of_verse} {start_of_verse: Plagal (IV-I)} [G]1 2 3 4 [D]1 2 3 4 [C]1 2 3 4 [G]1 2 3 4 {end_of_verse} {start_of_verse: Half (ends on V)} [G]1 2 3 4 [Em]1 2 3 4 [C]1 2 3 4 [D]1 2 3 4 {end_of_verse} {start_of_verse: Deceptive (V-vi)} [G]1 2 3 4 [C]1 2 3 4 [D7]1 2 3 4 [Em]1 2 3 4 {end_of_verse} ``` Play each line twice and listen: the authentic line feels finished; the plagal one finished but gentle; the half cadence leaves you hanging on D; the deceptive one sets up G and slips to Em. ## Cadences in popular music Common-practice cadence theory was built on classical music, and pop doesn't always obey it. Rock often uses ♭VII → I (F → G in G, or D-C-G loops) as a closing gesture, the blues ends a chorus on V in the turnaround (a half cadence that loops back to the top), and the I-V-vi-IV loop never truly cadences at all, which is part of why it can repeat forever. Recognising when a song avoids a strong V-I is as useful as recognising when it uses one. See [[AI Wiki - Music - Blues Music]] and [[AI Wiki - Music - Pop Music]]. ## On piano Practise cadences as small hand shapes in the right hand with the bass note in the left: in C, V7-I as B-D-F → C-E-G (or G-B-F → G-C-E), IV-I as C-F-A → C-E-G. Moving to the nearest notes trains voice leading and is the same skill used for smooth [[AI Wiki - Music - Piano Chord Inversions]]. Then play them in G, F and D. ## How to practise 1. **Play the chart above** in G, then transpose it to C, D and A (or use a capo; see [[AI Wiki - Music - Capo and Transposition]]). 2. **Sing the tonic.** After each phrase, sing the key note. After an authentic cadence you're already on it; after a half or deceptive cadence you'll feel the pull. 3. **Ear quiz.** Have someone (or an app) play a phrase ending; name it. Start with authentic vs half, then add deceptive and plagal. This is a core [[AI Wiki - Music - Ear Training]] skill. 4. **Spot them in songs.** For every song you learn, mark where each section ends and which cadence it uses. 5. **Swap them.** Change a song's final V-I to V-vi and hear how it refuses to end. ## Common mistakes - Confusing British "imperfect" (half) with American "imperfect authentic". - Playing a minor v in a minor key (Em → Am) and wondering why the cadence sounds weak: use E or E7. - Calling any I-V a half cadence: it's only a cadence if it ends a phrase. ## Key Points - A cadence is the two-chord ending of a phrase; it decides whether music feels closed or open. - Authentic (V-I) is the strongest; PAC = root positions with the tonic on top. - Plagal (IV-I) is the soft "Amen" ending, without a leading tone. - Half cadence ends on V and sounds like a question. - Deceptive (V-vi) sets up the tonic and swerves to the [[AI Wiki - Music - Relative and Parallel Keys|relative minor]]. - The leading tone in V (and the seventh in V7) creates the pull to I; minor keys need a major V for it. - UK and US names differ: perfect = authentic, imperfect = half, interrupted = deceptive. ## Open Questions - **Answered** ([[AI Wiki - Music - Modal Harmony|Modal Harmony]]): How do cadences work in modal music without a leading tone? They use ♭VII–I, ♭VII–IV–I (double plagal), IV–I, ♭VI–♭VII–i, v–i or ♭II–i, and rely on repetition, metric position, the bass and the melody to establish the tonic. - Which cadences do the songs I'm learning use at the end of verses vs choruses? ## References - Wikipedia, "Cadence": https://en.wikipedia.org/wiki/Cadence - musictheory.net, "Cadences": https://www.musictheory.net/lessons/55 - *First Year Music Theory* (Minnesota State), "Cadences": https://minnstate.pressbooks.pub/firstyearmusictheory/?p=1695 - Musicnotes, "Cadences in Music Theory: The 4 Types Explained": https://www.musicnotes.com/blog/cadences-in-music-theory-the-4-types-explained ## Related - [[AI Wiki - Music - Diatonic Chords and Roman Numerals]] - [[AI Wiki - Music - Common Chord Progressions]] - [[AI Wiki - Music - Minor Scales]] - [[AI Wiki - Music - Seventh Chords]] - [[AI Wiki - Music - Piano Chord Inversions]] - [[AI Wiki - Music - Capo and Transposition]] - [[AI Wiki - Music - Ear Training]] - [[AI Wiki - Music - Modes]] - [[AI Wiki - Music - Blues Music]] - [[AI Wiki - Music - Pop Music]] - [[AI Wiki - Music - Chord Progression Recognition]] - [[AI Wiki - Music - Circle of Fifths]] - [[AI Wiki - Music - Functional Ear Training]] - [[AI Wiki - Music - Jazz Music]] - [[AI Wiki - Music - Relative and Perfect Pitch]] - [[AI Wiki - Music - Solfege and Singing]] - [[AI Wiki - Music - Arranging Songs]] - [[AI Wiki - Music - Melody and Phrasing]] - [[AI Wiki - Music - Playing from Lead Sheets]] - [[AI Wiki - Music - Reharmonization]] - [[AI Wiki - Music - Sight-Reading]]