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

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)

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.

II⁷ (V/V, or V-of-V)

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-V-I. In this case, it’s major and minor are both equally valid options

• ex. Good Day Sunshine verse, Maxwells Silver Hammer verse
• 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)

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.

Scales in music are like the alphabet in a written language: you need to know the scales to write, but that alone will not get you to where you want to go. Typing out the alphabet over and over will not make you compose poetry better, but you need to know the alphabet to compose poetry.

Note Hierarchy

In a major scale, the most important notes are 1-3-5. This is due to the fact that they are chord tones— they exist in the major chord of that key. Next in importance are 2-6, since they are both whole steps away from their neighbors. Lastly are 4-7, which are considered least important due to the fact they are both a half step away from the chord tones (ie. the notes that make up the chord).

• If we switch to a minor scale, we will notice that the 2 also sounds more dissonant, due to the fact that it's now a half-step away from a chord tone (the minor 3rd). Likewise, the 4 becomes much more consonant in the minor scale, due to the fact that it's now a whole step away from any chord tone.
• note: "important" here is more defined in a sense that these notes do more of the heavy lifting for defining the sound of the key being played. If we examine a melody being played over a chord, what we most often find is the 1-3-5 being played on the downbeats. They represent the comfort zone of the key. Of course, melodies often incorporate the other scale degrees, but more often than not, these other notes are treated as roads to 1-3-5. Take the melody "Wrecking Ball", which starts on the 4, before resolving down to the 3 and then the 1. The 1 and 3 are only more important than the other scale degrees in a sense that they are what drive the melody forward.

Seventh

Over a seventh chord, the 7th scale degree (having previously been lowest on the note hierarchy) gets promoted to be equal in importance to 1-3-5. When we have a seventh chord, we want to make sure to hammer the 7th more than usual to bring out the quality of the chord.

• in fact, over a seventh chord the 1 starts to sound a little more dissonant than it previously had with a straight major chord. In the context of the seventh chord, the 1 kind of feels like it should resolve down to the 7. Therefore, we may decide to avoid the 1 a little more.

Scale characterizations

Chromatic

Chromatic refers to the presence of all 12 pitches, each separated by a semitone interval.

• sometimes we make a dichotomy between chromatic and diatonic. All that's to say is that chromatic refers to the notes/chords that don't belong (ie. not diatonic).

Diatonic

When we say something is "diatonic", we say that it belongs in the context (or more accurately, originates from the context. The analogy below makes this more clear). In other words, it belongs in the scale we are currently in.

• ex. In the key of Cmaj, the notes that are diatonic are C D E F G A B
• anal: the letter e is diatonic to the English language, but é is not
  • notable in this analogy is that there is nothing wrong with using non-diatonic letter in English, as in the word "naïveté".

A diatonic scale is a subset of a chromatic scale, since all notes of a diatonic scale exist in the corresponding chromatic scale.

Pentatonic

A pentatonic scale has 5 notes, made up of the chord tones (1-3-5), plus the 2 next notes in the note hierarchy

• in major, 2 and 6 are added. In minor, 4 and 7 are added.
  • in major the 4 and 7 are omitted due to their half-step distance from chord tones. The same is true of the 2 and 6 of minor

It is good to think of the pentatonic scales as your foundational scales. Every time you play melodies, think in terms of pentatonic, then add scale degrees that are lower in the note hierarchy as needed to add additional flavours. Seeing the pentatonic scales in this way forces us to be more deliberate about our use of the scale degrees that are half-steps away from chord tones.

Blues

The blues scale is a pentatonic scale with an added ♭V.

Scale Degrees

Subtonic

The degree of a scale that is a whole step below the tonic.

• thus, in a major scale it is non-diatonic, as the 7th is only a half step below the tonic, making the subtonic a flattened 7th.
• in a natural minor scale is it diatonic.

UE Resources

• Scales: Why They Matter and How to Practice Them
• Reference songs for interval recognition