6/4 Chord Function
So far, you have learned different ways you can expand the predominant function, both in major and minor keys, and you have realized that other chords like iii or VI may lose their function and work in a different way. For example, IV can serve as a predominant but also as an extension of the tonic.
Similarly, in music, we don’t usually see 6/4 chords functioning in the same way as normal triads. If you have a keyboard or piano near you, try playing a I chord in C Major. Now, invert the chord so that you’re still playing a I chord, but it is in second inversion, i.e. a I 6/4 chord. You will probably notice that the tonic quality of the C Major chord is far less prominent.
Similarly, a V 6/4 chord doesn’t really sound like a dominant chord, and a IV 6/4 chord doesn’t really sound like a subdominant chord. That doesn’t mean that we don’t use 6/4 chords at all, though. There are 4 main contexts in which we do use 6/4 chords in music: cadential 6/4 chords, neighboring or pedal 6/4 chords, passing 6/4 chords, and arpeggiated 6/4 chords.
Here is a brief overview of what all of these 6/4 chords do:
- Cadential 6/4 chords are used to embellish dominant chords before a cadence. Usually, we have a I 6/4-V-I progression, where the upper notes in the I 6/4 chord move down stepwise. For example, in C Major, a I 6/4 chord with notes G-C-E will have the upper notes move down so we have a G-B-D root position V chord.
- Neighboring or pedal 6/4 chords are 6/4 chords that are used to embellish the top lines of a piece of music. Imagine a I-IV 6/4-I chord in C Major. The note in the bass line, C, stays the same, while the upper notes briefly change before going back to where they started.
- Passing 6/4 chords are chords where the bass line is moving up or down, usually by a third, and we fill in this skip with a 6/4 chord to fill in the bass. For example, if we have a I-V 6/4-I6 progression in C Major, then the bass line will be moving up stepwise as C-D-E, and the upper notes will move according to our voice leading rules.
- Arpeggiating 6/4 chords are used to embellish the same triad. So, we might have a I-I6-I 6/4 chord progression, where the bass note is changing. In this case, the 6/4 chord does have the same chord function as it would in the other inversions, but it is used to embellish the preceding triads rather than to add harmonic value in some way.
The main takeaway is that for all of these 6/4 chords, we are embellishing the existing harmonic structure of the piece – we are not adding any more harmonies.
Cadential 6/4 Chords
In this section, we are going to dive a little deeper into cadential 6/4 chords.
The cadential 6/4 chord is a I 6/4 chord that precedes a root position dominant triad, usually at a cadence. Although the cadential 6/4 contains the notes of the tonic triad, it does not exercise a tonic function but serves as a brief expansion of the dominant area. For this reason, we usually say that the cadential 6/4 has a dominant function, and rather than writing I 6/4-V, we will usually notate this pattern as V 6–5/4–3 to indicate that the 6/4 chord is “part of” the V chord.
Usually, the cadential 6/4 chord is written in a metrically stronger position than the dominant chord that follows it, and the upper voices of the 6/4 chord will move downward by step to reach the dominant chord. For example, if we have a cadential 6/4 chord in A Major, then the 6/4 chord will have the notes E-A-C, and then A and the C in the upper voices will move down to G and B respectively to spell the root position dominant chord E-G-B. Then, we will use our traditional voice leading rules to resolve the dominant chord to the I chord. The I chord will usually be written on a strong beat.
When we write cadential 6/4 chords, it is good practice to double the bass of the chord (not the root, like in traditional voice leading). This means that the fifth scale degree will show up twice in the 6/4 chord, which will emphasize its dominant function.
Here is an example of a cadential 6/4 chord. Although we will usually use the notation V 6–5/4–3 notation to write a cadential 6/4 chord, here is another acceptable way to notate the cadential 6/4.
Resolving to the Dominant Seventh
Can I write a cadential 6/4 chord to precede a V7-I cadence? Of course you can! When we follow a cadential 6/4 chord by a dominant triad, we usually retain the dominant voice that was doubled in the 6/4 chord in the dominant triad. In the example above in Bb Major, the 6/4 chord had notes F-F-B-D, and in the triad, we had notes F-F-A-C (notice that the bass note in the 6/4 chord is a whole note, meaning that it is also heard in the dominant triad. That means that in the V chord, we retained both of the Fs as common tones, and the A and the C moved down stepwise.
If we want to go from a I 6/4 to a V7 chord, all we would have to do is move one of those Fs down. Since a third inversion V7 chord usually doesn’t have a strong dominant sound, whichever F is in an upper voice would move down stepwise to an E, spelling F-E-A-C, a root position V7 chord.
To notate this in music, you will write this chord progression as V 8–7/6–5/4–3 in order to indicate that the 8th above the bass moves down to the 7th above the bass, the 6th moves down to the 5th, and the 4th moves down to the 3rd. Note that just like in regular figured bass notation, it doesn’t matter what order the notes in the chord are really in. Even if the 8th of the chord was in the alto voice and the 3rd of the chord was in the soprano voice, you would still write the figured bass notation as V 8–7/6–5/4–3.
Here is an example of a cadential 6/4 chord moving to a V7 chord in a chord progression:
Voice Leading with the Cadential 6/4 Chords
First, remember to BOLD_PLACEHOLDER_6 of the cadential 6/4 chord. This reinforces the dominant function of the cadential 6/4 chord so that the 6/4 chord sounds like an embellishment to the dominant rather than a second inversion tonic triad. This also makes it easier to retain the common tone when moving to a dominant triad or move the doubled tone down stepwise to spell a dominant seventh chord.
Doubling the bass isn’t just a stylistic choice when writing cadential 6/4 chords. If you don’t double the bass, then the cadential 6/4 chord would be considered wrong in the AP Music Theory exam.
Second, it is a good idea to approach the cadential 6/4 chord with a predominant harmony, like a IV chord or a ii6 chord. This is usually just common practice when it comes to writing chord progressions: predominant harmonies should precede dominant harmonies. However, especially when writing cadential 6/4 chords, you should always have a strong predominant section.
There are two reasons for this. First, the cadential 6/4 loses its dominant function when preceded directly by the tonic section of a phrase, since the cadential 6/4 has a tonic harmony. Second, since the subdominant chords “want” to resolve to dominant chords, writing the cadential 6/4 between the subdominant and dominant harmonies creates good harmonic tension as listeners have to wait for the subdominant to resolve.
Cadential 6/4 chords should always go on a strong beat. Otherwise, the embellishment sounds too weak, and it will lose its musical effectiveness.
A quick note: If you write a cadential 6/4 chord correctly, you shouldn’t run into this problem, but you should always check for direct fifths and octaves in cadential 6/4 chords, since all of the upper voices are moving down stepwise in parallel motion.
Here are a few final examples to sum this section up:
- In the first chord progression, we see a cadential 6/4 chord solving to V. Notice how common tones are kept, and the other voices move down to the nearest tones.
- In the second measure, we see a cadential 6/4 solving to a V⁷ chord. See how the bass is kept the same, and SAT voices (Soprano, Alto, Tenor voices) all move down by step in parallel motion in order to resolve to the V7.
Frequently Asked Questions
What's the difference between a cadential 6/4 chord and a regular second inversion triad?
A cadential 6/4 and a “regular” second-inversion triad look the same on paper (both show the triad in 6-4), but they function differently. A cadential 6/4 is an embellishment of V, not a tonic: it appears in a metrically strong position right before the dominant and usually notated/functioned as V6/4–V5/3. The two upper notes (the 6 and 4 above the bass) resolve down by step to the 5 and 3 (PIT-2.K, PIT-4.E), so the chord doesn’t act as I; it’s voice-leading toward V. A regular 6/4 triad used as passing, pedal/neighbor, or arpeggiated 6/4 actually exercises its local function (as passing or prolongation) and doesn’t necessarily resolve the 6 and 4 down to 5 and 3. For AP exam practice and examples (including V6/4–V5/3 patterns and voice-leading rules), see the Topic 5.6 study guide (https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe) and try problems at (https://library.fiveable.me/practice/music-theory).
How do I identify cadential 6/4 chords when I'm analyzing sheet music?
Look for four clues together—if you see all of them, it’s a cadential 6/4: 1. Chord spelling: a tonic triad in second inversion (scale-degree order: 5–1–3 above the bass). It looks like I6/4 but functions differently. 2. Placement: it appears on a metrically stronger beat right before a dominant (V). The progression is usually notated V6/4–V5/3. (CED: PIT-2.K) 3. Voice leading: the upper voices form the 6 and 4 above the bass and resolve down by step to 5 and 3 when the V arrives (6→5, 4→3). That stepwise resolution is required (CED: PIT-4.E). 4. Function: it acts as an embellishment of the dominant, not as tonic—so treat it as part of the approach to V, not a separate I. Quick method when analyzing: label the chord as I6/4 first, check the next chord (is it V?), check metric position, then confirm the stepwise resolutions in the upper voices. For guided examples and practice problems, see the Topic 5.6 study guide (https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe) and more practice items at (https://library.fiveable.me/practice/music-theory).
I'm confused about why cadential 6/4 chords don't actually function as tonic chords - can someone explain?
A cadential 6/4 looks like a tonic triad in second inversion (the same three notes), but it doesn’t act as tonic because of its context and voice leading. It appears in a metrically strong spot immediately before V and functions as an embellishment of the dominant: the 6 and 4 above the bass resolve down by step to 5 and 3 (so you get V6/4 → V5/3 → V → I). Because the upper voices move stepwise into chord tones of the dominant and the harmony’s role is to intensify the approach to V, its harmonic function is dominant—not tonic (CED PIT-2.K.2, PIT-4.E.1). For AP exam part-writing, remember to resolve the 6 and 4 down by step and treat the chord as V⁶₄–⁵₃ in figured-bass realizations. For a quick refresher, see the Topic 5.6 study guide (https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe) and try related practice problems (https://library.fiveable.me/practice/music-theory).
What does V6/4-5/3 notation mean in Roman numeral analysis?
V6/4–5/3 is a figured-bass/Roman-numeral way to show the cadential 6-4 as an embellishment of the dominant. It tells you: treat the chord as V, but the upper voices form a 6–4 above the bass on the strong beat (the cadential 6-4), then resolve those intervals down by step to 5–3, producing the plain V chord. In other words, a tonic triad in second inversion (sounding like I6/4) is functioning as an ornament of V—not as a true tonic. Remember the AP CED rule: the 6 and 4 above the bass must resolve down by step (PIT-4.E.1), and V6/4–5/3 is exactly the figured-bass reminder of that voice-leading (PIT-2.K.2, PIT-4.E.2). For practice and more examples, see the Topic 5.6 study guide (https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe) and Unit 5 resources (https://library.fiveable.me/music-theory/unit-5).
How do I write proper voice leading for cadential 6/4 chords in my part-writing assignments?
Treat the cadential 6/4 as an embellishment of V, not as a tonic sonority. Practically: place the 6 and 4 above the bass so they each resolve down by step to become the 5 and 3 of the dominant (i.e., I6/4 → V5/3 or notated V6/4–5/3). Keep the upper voices mostly stepwise, retain any common tone between I6/4 and V when possible, and avoid large leaps or doubling the leading tone. Put the cadential 6/4 on a stronger metric position than the V that follows (that’s part of its function). Errors that cost points on AP part-writing: failing to resolve the 6 and 4 down by step, doubling the leading tone, or creating parallel perfects in the outer voices. For drill, study the CED items PIT-2.K.2 and PIT-4.E.1 and practice examples in the Topic 5.6 study guide (https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe). Want more practice? Use the Unit 5 review (https://library.fiveable.me/music-theory/unit-5) and 1000+ practice problems (https://library.fiveable.me/practice/music-theory).
Why do the sixth and fourth above the bass always have to resolve down by step in cadential 6/4?
Because a cadential 6/4 is not a tonic-function chord but an ornament of the dominant, the 6 and 4 above the bass must move down by step to become the 5 and 3 of V. In CED terms, the I6/4 appears in a metrically strong position and “serves as an embellishment of the dominant” (PIT-2.K.2). If you don’t resolve 6→5 and 4→3 by step, you fail to form the actual V sonority and you break 18th-century voice-leading rules (PIT-4.E.1). Practically: keep the bass stationary (often scale degree 1 becomes the bass of V), let the upper voices descend stepwise so the I6/4 reads as V6/4–V5/3 (figured as 6–4 → 5–3). On the AP exam, correctly resolving those voices is required in part-writing and error detection (see the cadential 6/4 study guide on Fiveable: https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe). For more practice, try the 1,000+ problems at (https://library.fiveable.me/practice/music-theory).
What are the four types of 6/4 chords I need to know for AP Music Theory?
You need to know four 6/4 contexts for the AP exam: cadential 6/4, neighboring (or pedal) 6/4, passing 6/4, and arpeggiated 6/4. - Cadential 6/4: a tonic triad in 2nd inversion that functions as an embellishment of V (not as tonic); appears on a stronger beat before the dominant and the 6 and 4 resolve down by step to 5 and 3 (V6/4–V5/3). This is emphasized in the CED (PIT-2.K, PIT-4.E). - Neighboring/pedal 6/4: tonic in 2nd inversion that neighbors a stable bass tone or sits over a pedal point. - Passing 6/4: fills stepwise bass motion (bass in passing tones) creating a temporary 6/4. - Arpeggiated 6/4: occurs when upper voices arpeggiate a chord while the bass sustains the root, producing 6/4 sonorities. For AP practice, study cadential voice-leading rules (6→5, 4→3) and try examples in the Fiveable study guide (https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe) and extra problems at (https://library.fiveable.me/practice/music-theory).
How can I tell the difference between cadential, passing, neighboring, and arpeggiated 6/4 chords?
Quick checklist to tell them apart: - Cadential 6/4: Happens on a strong beat right before V (often at a cadence). Looks like a tonic triad in 2nd inversion but functions as an embellishment of V (not tonic). Upper voices usually move down by step (6 → 5, 4 → 3); labeled V6/4–V5/3 in figured bass (CED: PIT-2.K, PIT-4.E). - Passing 6/4: Occurs on a weak beat in stepwise bass motion (e.g., I – I6/4 – V)—it’s a linear filling chord between two stable harmonies. - Neighboring/pedal (pedal) 6/4: Bass holds the same pitch while upper voices move to neighbor tones; pedal 6/4 often spans multiple beats with the bass sustained. - Arpeggiated 6/4: Produced by arpeggiation of a triad (notes spread in time). You’ll see common-tone retention and staggered entrances (not the stepwise resolution required for cadential). On the exam, ID each by meter (strong vs weak), bass motion (step vs stationary vs arpeggiated), and voice-leading (do the 6 and 4 resolve down by step?). For more examples and practice, see the Topic 5.6 study guide (https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe), Unit 5 overview (https://library.fiveable.me/music-theory/unit-5), and practice problems (https://library.fiveable.me/practice/music-theory).
I don't understand what "metrically stronger position" means when talking about cadential 6/4 placement.
“Metrically stronger position” just means the cadential 6/4 happens on a stronger beat (a downbeat or a longer-value beat) than the following V. Practically: the tonic triad in 6/4 is placed on a strong pulse as an embellishment, then the actual dominant (V or V6/5, notated as V6/5–V5/3 sometimes) arrives on a weaker beat or as the next chord. In common time you’ll often see I6/4 on beat 1 (strong) and V on beat 2 or the next weaker subdivision. The point for AP voice leading: treat the 6 and 4 above the bass as dissonant/embellishing tones that resolve down by step to 5 and 3 (PIT-4.E.1), and don’t give the cadential 6/4 tonic function—it’s an ornament of the dominant (PIT-2.K.2). For more examples and part-writing practice, check the topic study guide (https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe) and try problems at (https://library.fiveable.me/practice/music-theory).
What's the proper way to analyze cadential 6/4 chords for my portfolio - do I label them as I or V?
Label it as an embellishment of V, not as a functioning I. Even though the chord contains the tonic triad in 6–4, the cadential 6–4 does not have tonic function—it sits in a stronger metric position and resolves to the dominant (usually notated V6–4 → V5–3 or V6–4–5–3). For your portfolio write the Roman numeral as V with a 6–4 figure (or V6–4 → V5–3) and explain why: the 6th and 4th above the bass resolve down by step into the dominant, and upper voices move stepwise (CED: PIT-2.K and PIT-4.E). That shows you know it’s a dominant embellishment, not a tonic harmony. For a quick refresher, see the Topic 5.6 study guide (https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe) and try practice problems at (https://library.fiveable.me/practice/music-theory).
How do I fix voice leading errors in cadential 6/4 progressions?
First, ID the two notes forming the 6 and 4 above the bass in your I6/4—those are the tones that MUST resolve down by step to the 5 and 3 of V (CED PIT-4.E.1). Quick fix checklist: - Make the 6 → 5 and 4 → 3 by step in the upper voices (usually both move down). Think I6/4 → V (not I → V)—it’s an embellishment of the dominant (PIT-2.K.2). - Keep any common tone between I6/4 and V if possible (retains smoothness). - Avoid doubled leading tone, unresolved leading tone, and parallels (perfect 5ths/8ves) when voices move into V—check outer voices for hidden/direct octaves/fifths. - Double the bass or a stable chord tone, not the dissonant 4. - If you still see errors, redraw the soprano/alto motion so both resolve by step and re-check spacing/doubling. For examples and practice problems tied to the AP rubric, see the cadential 6-4 study guide (https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe) and Unit 5 review (https://library.fiveable.me/music-theory/unit-5). Practice more part-writing at Fiveable’s problem set (https://library.fiveable.me/practice/music-theory).
Why does my cadential 6/4 sound wrong when I don't resolve the voices stepwise?
Because a cadential 6/4 is an embellishment of V (not a tonic) it lives in a strong metric position and its two upper intervals (the 6 and 4 above the bass) are supposed to resolve down by step to the 5 and 3 of the dominant (V⁶₄ → V⁵₃). If you move those voices by leaps instead of stepwise, you break that conventional voice leading: the 6/4 won’t resolve, the chord loses its dominant function, and you can create awkward parallels, hidden/direct fifths, or unresolved nonchord tones. The AP CED explicitly requires the 6 and 4 to resolve down by step (PIT-4.E.1); on part-writing tasks an incorrect cadential 6/4 resolution is a voice-leading error (scoring notes: III.D.12). Fix: keep the bass (usually tonic) stationary, let the two upper voices move down by step into the thirds and fifths of V (you may keep one common tone). For more examples and practice, see the Topic 5.6 study guide (https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe) and Unit 5 review (https://library.fiveable.me/music-theory/unit-5).
What figured bass symbols show cadential 6/4 voice leading patterns?
Figured-bass for a cadential 6/4 is usually shown as the tonic in second inversion followed immediately by the dominant figured as V⁵₃—so you’ll see the figures 6–4 over the bass moving to 5–3 (often written V⁶₄ – V⁵₃ or just 6–4 → 5–3). Those numerals remind you that the 6th and 4th above the bass must resolve down by step into the 5th and 3rd of the dominant (CED PIT-2.K.2 and PIT-4.E.1). On AP tasks (especially Figured-Bass part-writing, Free-Response Q5), mark the 6–4 as an embellishment of V, not a tonic function, and show correct stepwise resolutions. For a quick review, see the Topic 5.6 study guide (https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe) and try practice problems (https://library.fiveable.me/practice/music-theory).
Can cadential 6/4 chords appear anywhere besides cadences or do they have to be at the end of phrases?
Short answer: they don’t have to be only at the very end of a phrase, but they do have to function like a cadence—metrically strong and immediately embellishing a following V. Explanation: the CED says 6–4 triads are allowed only in four contexts (cadential, passing, neighboring/pedal, arpeggiated). A true cadential 6–4 “precedes the dominant, often at a cadence” and is in a stronger beat than the V; its 6 and 4 resolve down by step to form V (see PIT-2.K and PIT-4.E). So you can see a cadential 6–4 mid-piece if that spot is acting like a local cadence (e.g., a phrase boundary or tonicization)—but if it’s just filler on a strong beat without resolving to V as an embellishment, it’s not a cadential 6–4. For more examples and practice, see the Topic 5.6 study guide (https://library.fiveable.me/music-theory/unit-5/cadential-64-chords/study-guide/Fmolx6ik4nmpMVO4inHe) and Unit 5 review (https://library.fiveable.me/music-theory/unit-5). Practice questions are at (https://library.fiveable.me/practice/music-theory).