Does melody note function change with each chord change in a certain harmonic field?

Question

Lets say the root is G. The chord progression starts with a G minor chord (Tonic) and is in Aeolian mode.

Perfect fifth of it is D. etc..

Does a chord change change the function of the original notes?

If the melody is originally lets say going back and forth between D (Perfect Fifth) and C (Perfect Fourth) related to the root chord.

Then the same pattern continues but on the next chord that is F Major (Dominant).

Does the function of the notes change during chord changes so that every chord has its own perfect fifth etc. Or is the Interval system overarching in the harmonic field ? I understand that if the notes are a part of the underlying chord, there is a lot more consonance.

---- Basicly I'm asking if the thing below this text, is overarching or related to each individual chord change or both?

1: Perfect consonances: unison, octave, fourth, fifth. 2: Imperfect consonances: major third, minor third, major sixth, minor sixth 3: Dissonances: minor second, major second, tritone, minor seventh, major seventh

Answer 1

The term that you are looking for to discuss this is qualia. The example that you gave is terrific, but this one may be even more clear:

The example is in C major. In m. 1, the asterisked chord is V (dominant) with a B on top; this is scale-degree 7—also known as the leading tone—and it has a definite urge to resolve back up to tonic, which it does.

But in m. 3, this leading tone is harmonized not with a dominant-functioning V, but with a more enigmatic iii chord. As such, it happily resolves down to scale-degree 6, and we don't get the sense of a non-resolved leading tone like we would had the B in m. 1 not resolved up to tonic.

Thus we recognize that the harmonic context changed this most charged of tendency tones; the change in harmonic environment undoubtedly altered the qualia of this scale degree.

Answer 2

If I understand the melody notes and chords you describe, I came up with this notation:

X: 1
K: Gm
L: 1/4
%%staves {(RH) (LH)}
V: RH clef=treble
V: LH clef=bass
%
[V: RH] "5th"d/2"nt"c/2 "5th"d/2"nt"c/2 | "nt"d/2"5th"c/2 "nt"d/2"5th"c/2 | "3rd"d2 |
[V: LH] "i"[G,2B,2D2] |"V7/III"[F,2A,2E2] |"III"[B,,2B,2D2]|

The term "function" has a very specific meaning in harmony where we have tonic, pre-dominant, and dominant functions.

"Function" in a melodic context is sort of generic, but a few specific functional melodic ideas apply to your question:

• chord versus non-chord tones, various labels are given to melodic tones that do not belong to a chord like appoggiatura, suspension, neighbor tone, etc.
• tendency tones, some melody tones have a tendency to move a certain way, for example the ^7 scales degree - the leading tone - has a tendency to move up to the tonic.
• chord tone role (I'm not sure role is the best word, but I don't know a standard term) chord tones have names like root, third, fifth, etc. and can receive special consideration depending on the role, for example the third of a chord is general required because it defines the major or minor quality of the chord while the fifth can sometimes be omitted as not absolutely essential for defining the chord.

I labelled the music to show...

• neighbor tones (nt)
• and chord tones which were fifths and third

To get to your main question...

Does the function of the notes change during chord changes

...the answer is: yes.

Notice of the "C" in the melody is a non-chord tone when played over Gm but becomes a chord tone of the fifth when played over F7. And while the "D" in the melody is a consonant chord tone of a fifth over the Gm it becomes the chord third over the Bb chord.

I made a slight change to the harmonic context you gave and made the second chort a D7 the dominant in G minor.

X: 2
K: Gm
L: 1/4
%%staves {(RH) (LH)}
V: RH clef=treble
V: LH clef=bass
%
[V: RH] "5th"d/2"nt"c/2 "5th"d/2"nt"c/2 | "root"d3/2"7th"c/2  | "3rd"b,2 |
[V: LH] "i"[G,2B,2D2] |"V7"[^F,2A,2D2] |"i"[G,2B,2D2]|

I did this to illustrate a point about tendency tones with the two specific melodic tones you gave: "D" and "C". In your original harmony the "C" isn't a tendency tone. In fact, over the F7 chord it is a stable fifth of the chord. But, when the "C" is played over D7 it becomes the seventh of a dominant seventh chord which is a tendency tone that resolves down to the third for the following Gm tonic chord.

Note that in both examples the second chord is a dominant seventh chord. Merely selecting any dominant didn't determine how the "C" would function. We need to know specifically where each dominant would resolve to truly understand the function of the "C".

By changing the harmony we made the pitch "C" stable in one context but an un-stable tendency tone in another context!

Most harmony textbooks will include sections about non-chord tones, tendency tones, and other functional ideas where melody intersects with harmony. Try to review those topic in a textbook for more examples and explanation.

Answer 3

Both and more: the scale degree of a pitch class can be thought of as relative to several things:

• The current underlying harmony/chord.
• The previous one.
• In anticipation of the next one.
• In anticipation of the ultimate one.

Answer 4

When we refer to different notes by numbers, there are generally two ways this takes place. On the one hand, we will refer to a note as a number in the context of a key. We would generally refer to this as "scale degree #". On the other hand, notes can be referred to as they relate to a given chord. It gets a little strange when we start to refer to non-chord tones in relation to a chord. In some instances, it may not sound right to refer to a note as a number in relation to a chord if it is a non-chord tone but in other instances, it is fairly common. For example, in Classical theory, we may refer to a non-chord tone in terms of a suspension. In the context of Jazz, there aren't exactly non-chord tones, per se, so we can usually refer to these notes as numbers but they are usually described as extensions (2=9, 4=11, 6=13), though that isn't always the case (there's a bit too much here to go into a full on example though, so if that is of interest to you, it would best be asked as a separate question.

As far as the consonances and dissonances you are referring to, those are generally referring to intervals. They are relationships between two notes and are not specific to a given key. There are some ways that a given note can be described as having a general dissonance within a key even if they are consonant within the current chord, such as the leading tone generally having a sense of dissonance and wanting to resolve to the tonic.