A function describes the relationship between a chord and a tonal center, all in the context of the harmonic progression.

Tonic function

• stable chords of a key.
• In major: I iii vi. They are stable because their triads (ex. C E G) all contain the key's third scale degree (ex. Here, all C E and G chords contain an E).
• In minor: i ♭VI⁶ ♭III Has 3rd but no 4th

The third is the most important note for defining the scale's overall sound (modality)

Subdominant function

• bridge chords between other 2 functions. These chords take you away from home rather than lead back home.
• In major: ii IV. How these chords feel changes depending on if we are using triads or 7th chords. The IV triad contains the root of the key, giving it a little more stability. Meanwhile, the ii lacks the root, making it sound more adrift. The 7th of that chord happens to be the tonic, giving it more stability
• Has 4th but no 7th
• Chord contains the tonic note of the mode (c)

Common melodic resolutions are 5 -> 1, 2 -> 1, 7 -> 1

In minor, the 4th is usually a iv⁷

Dominant function

• unstable chords that provide tension and point back to tonic. Main engine that drives songs forward.
  • it is unstable because of the characteristic leading tone
• in the major scale, if we add a 7th it adds even more instability, thus making it have more gravity in wanting to point back to the tonic (ie. it makes the dominant function of the V scale even more dominant by making it a V⁷)
  • ex. In C Major, it doesn't matter if we use a G or a G7 as our V chord, since both of them contain a B, which is the leading tone (ie. 7th scale degree) of the C Major mode.
• In major: V vii°. They both contain the 7th (leading tone) and 2nd degree of the scale. These notes circle around the tonic and want to collapse in toward it.
• Has 7th but no 3rd

Playing the V keeps the music from resolving

In Minor

In minor keys, though, we actually have two forms of the seventh scale degree:

• Natural minor: The seventh degree is a whole step below the tonic (e.g., in A minor, it’s G). This G doesn’t have the same strong pull towards A; instead, it has a more subdued, ambiguous sound.

• Harmonic minor: To create a similar tension to major keys, we raise the seventh scale degree to create a half-step leading tone (e.g., G# in A harmonic minor). This leads to a V7 chord that can still pull strongly toward the tonic in a minor key (E7 in A minor, for instance).

• Doesn't really exist in natural minor, because there is no leading tone in minor, which dominant needs. However, the harmonic minor scale does include a leading tone, which effectively brings back the sense of wanting to resolve to the tonic.

  • this is only partially true, because the V chord can still create tension to make us want to return to a i. It all depends on context really.

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. 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 major scale notes without the 4th or 7th scale degrees

• 4th and 7th are omitted due to their half-step distance (and therefore dissonant) from the 3rd and 1st, respectively.

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