Function

A function describes the relationship between a chord and a tonal center within the context of a harmonic progression. Chord function is determined by harmonic context, voice leading tendencies, and the chord's role in establishing or departing from stability.

Tonic Function

Tonic chords provide stability and a sense of resolution or rest. They represent "home" in the key.

In Major: I, iii, vi

• The I chord is the primary tonic, containing the tonic note in the bass
• iii and vi share two notes with the tonic triad, giving them tonic qualities
• vi is particularly stable as it often substitutes for I in deceptive cadences
  • ex. coda of "Octopus' Garden"

In Minor: i, ♭VI, ♭III

• The i chord is the primary tonic
• ♭VI and ♭III share the tonic function through their close relationship to the tonic triad
• These chords provide stability without the strong pull toward resolution

A tonic can serve as a "temporary" dominant by turning it into a 7th or 9th chord. By doing this, it makes a movement to the IV chord much easier. In fact, this movement to IV can be thought of as a V⁷-I movement, if we consider that what was formerly our IV is now a new (temporary) home. This has been used as a tool to modulate the song during a bridge section, for example. In this process, the I appears to relinquish its status as the home tonality, as it moves convincingly to the IV chord.

• ex. start of bridges of "Hey Jude", "Revolution", "Oh Darling", "If I Fell", "This Boy".
• this works because, for example, a chord change from C-F is not merely a I-IV in the key of C, but also can be dressed up as V⁷-I in the key of F. In this case, the priming of the new tonal center happens because of the seventh chord.

Subdominant Function

Subdominant chords create movement away from tonic stability. They build tension but in a different way than dominant chords— they tend to "drift" rather than urgently pull toward resolution.

In Major: ii, IV

• IV contains the tonic note, giving it some stability while still moving away from home
• ii lacks the tonic note entirely, creating a sense of departure
• Adding 7ths changes their character: ii⁷ becomes more stable due to voice leading tendencies, while IV⁷ adds dissonance

In Minor: ii°, iv, ♭VII

• iv is particularly common, often appearing as iv⁷
• The subdominant function helps establish the minor mode through the lowered sixth scale degree

Key Characteristics:

• Create harmonic motion away from tonic
• Often contain the fourth scale degree, which wants to resolve down to the third
• Frequently precede dominant chords in progressions

Usage

The IV-iv minor 'miracle' move

• Try going from the normal major IV chord to a minor iv chord before returning to the tonic
  • ex. In My Life, Til There Was You

Dominant Function

Dominant chords create instability and tension that strongly pulls toward tonic resolution. They are the primary driving force in tonal harmony.

Generally speaking, the role of the dominant is to prime (intensify) the resolution to the next chord in the circle of fifths movement.

In Major: V, vii°

• Both contain the leading tone (7th scale degree), which creates strong pull toward tonic
• V⁷ intensifies this pull by adding a tritone between the 3rd and 7th of the chord
• The tritone resolves inward: leading tone up to tonic, 4th scale degree down to 3rd

In Minor: More complex due to the absence of a natural leading tone

• Natural minor: ♭VII and v lack the leading tone, creating weaker dominant function
• Harmonic minor: Raises the 7th scale degree to create a leading tone, enabling strong V and vii° chords
• Common to borrow V and V⁷ from the parallel major to strengthen dominant function

Voice Leading in V⁷-I Resolution:

1. Leading tone resolution: 7th scale degree resolves up to tonic
2. Tritone resolution: 4th scale degree resolves down to 3rd scale degree
3. Root movement: Strong progression by descending perfect fifth

Contextual Notes:

• Dominant function depends heavily on harmonic context
• Even in natural minor, context can give ♭VII or v dominant-like function
• Secondary dominants extend this function to tonicize other keys temporarily

Secondary Dominant

Chords built on other scale degrees (usually ii, iii, vi; the minor triads) can serve as secondary dominants by raising the 3rd a semitone and adding a 7 (so ii becomes II⁷, iii becomes III⁷, and so on)

• Though these are labeled dominants, they need not always contain the seventh, as is the case for the primary dominant (ie. V and not V7)

Essentially, we can make the ii, iii and vi scale degrees into dominants (meaning, we raise the 3rd a semitone and optionally add the 7th). This sets it up nicely to hit the chord that would be the I of that secondary dominant. This is useful if we are in a different key (say, for a bridge) and want to return to the songs main key. If the song were in Gmaj and we modulated up a 4th to C for the bridge, we could end the bridge on the D7 to launch us to the tonic of G.

Given that the cirle of fifths shows us the relationship between 5th scale degrees, we can see how each of these secondary dominants relate to the home key of the song, and we can see how each secondary dominant can lead us to certain places.

When looking at secondary dominance, our natural question may be, why have a non-diatonic note? The answer is to propel a chord sequence with added impetus while providing scope for a new melody note from outside the parent scale.

• Just like the primary dominant, the function of the secondary dominant is usually to intensify the resolution to the next chord in any cycle of fifths movement.
• Effectively, it is just another V-I move.

The basic idea is that you can alter one of the chords (usually the minor ones) in a major key, and then imagine what you were playing was the fifth. This gives it a priming effect that empowers the move to that chord's I.

• ex. If we were playing in the key of D major, the sixth of that key would be A minor. If we make it serve the function of secondary dominant, then it becomes B major 7. The B major 7 would be the fifth of the E. So by making the sixth major and adding a seventh, it primes us for a move to the E major or E minor, since B is at the 5th scale degree of the key of E.
• ex. Consider the very first chord progression of Maxwell's Silverhammer. It starts on D major, and then it goes down to the sixth, but the sixth is not minor, it is major, and it has the seventh. From here, it moves to the E minor. Turning that minor sixth into a major sixth primes the following V-I movement.

To add even more distance to make an even more satisfying resolution consider using diminished chords. Take for instance the song "Moon River". It descends the circle of fifths quite a long way starting with a sharp for that is voiced as a diminished seventh chord. From there it goes into its V, followed by the next V and so on until it arrives at E major.

• What’s notable in this progression is that the V of that diminished seven chord is a major seventh, and then the fifth of that chord is a minor seventh and then the fifth of that chord is a major seventh, and then the fifth of that chord is a minor seventh, and the fifth of that chord is a major seventh and the fifth of that is an E major which is the home key of the song, so it alternates between major and minor as it’s doing the fifths descent, but it’s important to note here is the part of about how we start this 5th by using a very descendent diminished seventh chord to lead into the next chord which is the 1 of that diminished seventh chord.

Using Diminished Chords for Extended Circle of Fifths Progressions

• To add even more harmonic distance and create a more satisfying resolution, consider using diminished chords to launch an extended circle of fifths descent.
• Take "Moon River" as an example. It travels quite far around the circle of fifths, starting with F#°7. From there, it moves through successive dominants - each chord functioning as the V of the next - until it finally arrives at E major.
  • What's particularly notable about this progression is the pattern that emerges as it descends through the circle of fifths: the fifth of each chord alternates between being a major seventh and a minor seventh chord. Starting from that diminished seventh chord, the fifth of that chord is a major seventh, then the fifth of that chord is a minor seventh, then major seventh, then minor seventh, then major seventh, and finally the fifth of that last chord brings us to E major - the home key of the song.
  • So the progression alternates between major and minor seventh qualities as it executes this fifths descent.
  • The key insight: Using a diminished seventh chord to begin this circle of fifths descent creates maximum harmonic distance from the home key, setting up an extended and highly satisfying resolution when the progression finally returns home.

II⁷ (V/V, or V-of-V)

• ex. I Will (on "when we're apart")
  • consider how the effect is to almost briefly modulate the song to C (the V of the song's main key of F)

VI⁷ (V/ii, or V-of-ii)

Hitting the VI7 adds one more step to the progression. Instead of going from II-V-I, we wind it back one more step and go VI-(ii/II)-V-I. In this case, it’s major and minor are both equally valid options

• ex. Good Day Sunshine verse, Maxwells Silver Hammer verse, Mr. Moonlight (on "fine")
• VI7 is most obvious as a turnaround device at the end of a song. It is frequently used by the Beatles as a repeated tag that takes us around the block with VI7 repeatedly priming the II-V-I (or ii-V-I) cadence. Ex. Little Child ending, Her Majesty ending

III⁷ (V/vi, or V-of-vi)

In the vii-III-vi progression, the vii is often played as minor instead of diminished

This progression takes us to the vi chord in a far stronger way than if we just jumped to it directly from the home tonic

Ex. Here, There and Everywhere; Yesterday (opening chord); Moon River (from Breakfast at Tiffany’s)

Don't forget, when you're playing in a minor key, your key is also the vi chord of the parallel minor. If we're playing in Am, our Am can be made into a secondary dominant by making it an A7 (vi->VI7), which can facilitate a "key change" to C.

VII7 (V/iii, or V-of-iii)

Not used as often as the other secondary dominants, but it's used in a similar way, which is to point to its I (ie. iii of the current key) but used in a similar way, which is to point to the

• ex. Sexy Sadie

I7 (V/IV, or V-of-IV)

Interestingly, the 5th of the 4 is the tonic that we've been playing in. Often the way that this is used is to modulate to a different key.

• ex. Imagine we're in C and want to modulate to F. What we could do is have our verse end on C, and half of the time that the C chord is playing, it turns into a C7. This makes the pull to the F much stronger, since the C is now acting as the fifth of the F.

Non-Functioning Secondary Dominant

A non-functioning secondary dominant is a secondary dominant that does not treat the dominant as a V to be resolved to its I

II⁷

The most interesting capability of this one is the dark, sometimes "rocky" minor third interval between the II and the IV

• ex. Sgt. Peppers Lonely Hearts Club Band during verse (I-II⁷-IV-I), You Won't See Me (verse), Eight Days a Week (verse)

III⁷

• ex. I Want To Hold Your Hand (the dominant chord that leads into the chorus, on the word "hand")

Pre-dominant

A pre-dominant is a chord that supercharges the V chord.

• this is (usually or always?) provided by inherent voice-leading that occurs in the progression
  • ex. in ♭VII-V7-I, we have a chromatic ascent

Examples

• ♭VII-V7-I
• IV-V7-I
• ii-V7-I
• II7-V7-I

Other borrowed chords

iv (minor subdominant)

Substitute a IV for a minor iv. Especially effective as a iv6 chord

• ex. I'll Follow the Sun (during bridge "and so my love I must go), Nowhere Man ("...nowhere plans for nobody"), Real Love (in pre-chorus "No need to be alone")

v (minor dominant)

The minor dominant is a sure-fire method of creating tension and interest, particularly when providing support for a ♭7 in the melody (making it a v⁷).

• The tension results from the fact that the v7 chord contains the ♭7, 9th, and 11th scale degrees of the tonic. As a result, that v7 chord creates the sound of the I chord with extensions, like a I⁹ or I¹¹, albeit with a more mellow and ambiguous quality.
• ex. Strawberry Fields Forever, at "let me take you down cause I'm going to".
• ex. She's Leaving Home, at "Wednesday morning at 5:00"
• ex. Sun King, at "here comes the sun king"

a ♭VII is essentially a rootless v7

• ex. in key of C, ♭VII = B♭-D-F, v = G-B♭-D-F

Minor dominants can often be found where there might have otherwise have been a dominant tonic. For instance, if we're playing in the key of C and we were going to play a C7, we can substitute that for a G minor 7. The reason is that the 7 of that C7 chord also exists in the G minor 7 chord.

• expl. If we take Sun King by the Beatles, which goes C, C major 7, the leading tone of that transition is a chromatic descent starting on the C then going to B. There is momentum to land on a C7 there because that continues on the chromatic descent to a Bb. However, Sun King does not go From C to C major 7 to C7. Instead of going to C7, it goes to G minor 7. And the reason why this works as a substitute is that C7 and G minor 7 both have that B flat in it. For an example from the same album where the chromatic descent is further made on the C7, look at something. In this case it goes from C to Cmaj7 to C7, which then sets it up for a resolution to F (the V).

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Substitutions

A substitution is when you replace one chord with a different chord that serves a similar harmonic function, while adding a different color or feeling to the music.

Substitutions work when the replacement chord:

• Shares common tones with the original chord (ideally 2+ notes, but 1 can work as well to a lesser extent)
• Maintains similar harmonic function (both chords want to resolve to similar places)
• Contains the critical tension notes that drive the progression forward

The more notes in common between two chords, the more likely that they can share a similar harmonic function, leading them to be stronger substitutions.

Related chords

Similar to how the I and vi are connected, so too are the IV and the ii. In any key, the ii is the relative minor of the IV. Therefore, a potential for substitution between these two chords exists

• Also, the 3rd of the ii wants to resolve to the root of the IV chord (ex. Opening chords of My Sweet Lord). Even more emphasis could be added if we use the ii7, since it pulls down to the 3rd of the V.
• When we substitute the iii for the I, we are gaining new melodic opportunities, due to the presence of the natural 7th note of the scale, which is a chord tone of the iii (in C, this is Em, which contains a B; the 7th scale degree of the C major scale)

The tonic family (stability) - I, vi, iii The subdominant family (movement away from the tonic) - IV, ii The dominant family (movement toward the tonic) - V, vii

ii7-for-IV

This substitution works because the IV and ii7 share 3 notes in common.

• ex. A major contains: A - C# - E, F#m7 contains: F# - A - C# - E

  • Shared notes: A, C#, and E (three out of four notes!)
  • F#m7 is essentially A major with an added 6th (F#) in the bass. They're very closely related chords.

• ex. She's Leaving Home, at "how could she treat us so thoughtlessly". This line vamps between ii7 and V, but the melody would still be properly supported if it was reharmonized to vamp between IV and V.

v7-for-I Dominant Minor Substitute

See minor dominant

Anytime we go to play a dominant 7th chord, instead we can substitute in the minor 5th of that chord.

• ex. If we are going to play a C7, we can instead play a Gm7. Because the G is the 5th of the C.

♭VI-for-iv

As we move between the iv and the ♭VI, we maintain two shared tones: the root of the iv becomes the third of the ♭VI, and the ♭3 of the iv becomes the root of the ♭VI. Given that these two chords have two notes in common, this is a reasonably strong substitution.

• The ♭VI chord is substituting for the iv (minor 4) chord. Both ♭VI and iv are closely related because ♭VI is the relative major of iv - they share the same notes, just with different roots.
• We might wonder "when do we ever see iv in pop music?", but the reality is: more than you think. A common progression is IV-iv. This is an opportunity to make the substitution to IV-♭VI.
• note: the ♭VI is the relative major of the iv in the same way the I is the relative major of the iv (notice that relative chords are always a minor 3rd apart)

on the piano it's easy to see why this substitution makes sense. If we were to play the second inversion of F-minor with F octaves in the left hand and we simply play an A flat instead and lower the highest note in the right hand by a whole tone, then we have an A♭maj. Thus, there There are two shared notes between these chords, making them viable substitutions.

• ex. In "It Won't Be Long," the verse vamps between E major and C major, which is a vamp between I and ♭VI. The underlying progression works as I - iv (E major - A minor). If you hum the melody over just E major and A minor, it works perfectly. The Beatles substituted C major (♭VI) for A minor (iv), creating a brighter sound with stronger bass movement (E to C is a minor 6th down, vs E to A which is a 4th up). The non-diatonic ♭6 in the melody necessitates using either iv (Am) or its relative major ♭VI (C major) to harmonize properly, as the diatonic 6 (C#) would clash with the melody's C natural.

an alternative to the ♭VI is the ♭VII, since these chords share 2 notes

• as such, ♭VII is another substitute for iv (In particular, it is a reverse dominant minor substitution)
• we can see why this move makes sense very easily on the piano If we play the second inversion of F minor with bass octaves in the left hand, and then we simply play B-flat with the left hand instead of F. this gets us very close to the ♭VII chord (we're just missing the 3rd).

♭VII

♭VII is the relative major of v

♭VII as a 'pre-dominant'

• see pre-dominant A common Cadence is ii-V7-I. Extra tension can be added by adding a ♭VII, supercharging the dominant in the process to make it even more impactful. Adding this chord in, the progression then becomes ii-♭VII-V7-I. A ♭VII headed for V keeps the song dramatically in motion
• We'll see that with the ♭VII thrown in there, it lessens the need to land on the I, and we're able to end the progression on the V7.
  • ex. All My Loving verse, at "...always be true"
• An interesting thing about this progression is that it provides ascending chromatic voice leading.
• The ♭VII-V7-I move involves a chromatic melody (via voice leading), making the final landing on the topic all the more impactful.
• ex. in Help, the progression is ii-♭VII-V-I, which contains 4 ascending chromatic leading tones
• ex. No Matter What by Badfinger

♭VII as a 'doo-wop turnaround'

The ♭VII can be used as a substitute for the vi in the doo-wop progression I-vi-IV-V, yielding I-♭VII-IV-V.

• ex. The Night Before verse
• ex. The Word verse

♭VII as a dominant

♭VII-I can effectively sub in for a V-I (perfect) cadence

• ex. Help! end of verse
• ex. A Hard Day's Night verse
• ex. For No One end of verse

♭VII9-for-iv

Given a minor chord, we can substitute a dominant 7th chord 4th higher.

Recall that iv is often played immediately after IV

Tritone substitution

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Section transition chords

A chord progression is only as good as what came before it. consider two cases of Beatles songs where the chorus was primed by a dominant seventh chord Lord.

• In I am the Walrus, right before the chorus there is a B7 chord (a II7) that seems out of place given the rest of the progression. It exists there to prime the chorus that immediately follows, which is a more straightforward ♭III-IV-V.
• In I want to hold your hand, at the end of the verse it again lands on a B7 chord which serves to prime the following chorus, which is a more standard progression.
• In both cases, we have an AWOL secondary dominant whose task is to kickstart a chorus by ascending first by a half step and then to culminate with a standard 4 to 5 move to the dominant.
  • Looking at it this way helps explain how the listener is pulled along by the force of the move in both songs. The only difference is that in Walrus, the move starts on II7 rather than III7, which allows allows it to accommodate precisely the desired hard rock flavor of the ♭III as it makes the extra stop on the journey to the dominant.

Functional Progression Patterns

Common progressions:

• T-S-D-T: The fundamental harmonic cycle (e.g., I-IV-V-I)
• T-D-T: Direct tonic-dominant relationship (e.g., I-V-I)
• S-D: Subdominant frequently leads to dominant (e.g., IV-V, ii-V)

Important: Function is contextual—the same chord can serve different functions depending on its placement in the progression and voice leading context.

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Backlinks

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• Function
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