Music Theory / Diatonic Function discussion, Chord Progression analysis thread

[Quaint88]

I'm not sure what to expect here, but I didn't see any threads on music theory, diatonic function, or chord progression analysis, so I thought I'd start one and see what happens. I've studied music theory a little off and on over the years, but I'm currently trying to really dig in on what makes chord progressions work. I'm looking to figure out at least somewhat objectively why something sounds good to my ear, then I want to find other candidates based on that and work backwards to find other things that sound good. I'm also working on a better understanding of key changes. I used to think of the key a song is in as the first chord you played most of the time, but I've since found that there's more to it than that, and there are often many key changes in even the simplest of songs / chord progressions.

Anyway, I'm hoping that we can analyze chord progressions that appear over and over in Western music (as well as some unusual ones) in the context of diatonic function (particularly the key changes). I'm also interested in a discussion of the scales one might use when improvising over the chord progression. Anything else music theory related is also welcome here.

Disclaimer: I am trying to learn this stuff, so if something I post looks off, it could very well be wrong. Don't hesitate to point it out or question it, please. It will only help me.

 

[Quaint88]

I'll start with a song most of us know: Amazing Grace in C Major. We always played it "with all of the minors", meaning that we added some chords to the progression that weren't really there for variety (you can only camp out on the I for so long).

Here are the chords we used:
C C7 F C Am D G G7 C C7 F C Am G G7 C

We start out with the I (C), but then we hit a 7th chord (C7) when the flat 7th (Bb) isn't in the scale of the key (it should be B since we were in C). I didn't understand this for the longest time, but I adjusted by ear. Now I understand that we were changing keys to F (the IV) and playing the V of the IV to get a stronger resolution when we change chords to F (the IV) than the resolution of I to IV.

 

[Quaint88]

Can anybody explain what is happening when we go to D Major in the chord progression? That was another one that I was able to adjust to by ear but didn't understand until fairly recently.

 

[VolunteerHillbilly]

Interested to see where this goes although it's over my head.

 

[pismonque]

Interested to see where this goes although it's over my head.

Agreed. I have nothing to offer but I will follow it. I like the curiosity of your approach, OP.

 

[vollygirl]

All I know is, there is nothing better than hearing a song and the musician or singer goes to the note you expect to hear.

 

[Chris4Vols22]

Can anybody explain what is happening when we go to D Major in the chord progression? That was another one that I was able to adjust to by ear but didn't understand until fairly recently.

Without listening to it, I'm gonna say the D chord is a secondary dominant, much like the C7. The key is C major, C7 is V7/IV, and IV is F, which is why C7 is followed by F. Same logic to the D: D is V/V, and V is G.

Study secondary dominants if you haven't already. They're all over the place in all music, and you be able to easily identify them when you get your head wrapped around it.

 

[Chris4Vols22]

Just reread your OP. You're not changing keys in this progression, it's secondary dominants. You pick a chord in the key of C and figure out its own dominant chord. For example (pertaining to your Amazing Grace study), in the key of F major, C7 is the dominant. However, C7 doesn't squarely fit in the key of C because of the B-flat. So, the point of the C7 is to temporarily tonicize the following F chord. It kinda gives a sense of changing keys, but without actually doing it. Generally, a full key change requires a cadence in the new key. We don't have a cadence in any key other than C in this example.

 

[vollygirl]

This would be so much better with audio clips!

 

[Quaint88]

Just reread your OP. You're not changing keys in this progression, it's secondary dominants. You pick a chord in the key of C and figure out its own dominant chord. For example (pertaining to your Amazing Grace study), in the key of F major, C7 is the dominant. However, C7 doesn't squarely fit in the key of C because of the B-flat. So, the point of the C7 is to temporarily tonicize the following F chord. It kinda gives a sense of changing keys, but without actually doing it. Generally, a full key change requires a cadence in the new key. We don't have a cadence in any key other than C in this example.

Thank you for explaining that! I was never clear on what makes tonicism distinct from a key change (I thought it was accidentals vs. a change in key signature), but now I understand that I was mistaking tonicism for key changes.

 

[Quaint88]

Without listening to it, I'm gonna say the D chord is a secondary dominant, much like the C7. The key is C major, C7 is V7/IV, and IV is F, which is why C7 is followed by F. Same logic to the D: D is V/V, and V is G.

Study secondary dominants if you haven't already. They're all over the place in all music, and you be able to easily identify them when you get your head wrapped around it.

That's the same thing I have (except I mistakenly thought the use of the secondary dominant meant a key change instead of tonicism).

I think those are the most interesting parts of that chord progression, but do you see any others before I move on to another?

 

[davethevol]

Thank you for explaining that! I was never clear on what makes tonicism distinct from a key change (I thought it was accidentals vs. a change in key signature), but now I understand that I was mistaking tonicism for key changes.

Another thing to look at is the resolution of the 7th (B flat) to the 3rd (A) of the next chord. It’s taught in jazz and blues.
Soloing over Standards and Jazz Blues with "Functional Harmony” - METRONOME ONLINE - free online metronome

 

[hog88]

This is like trying to read a thread written in Greek.

 

[n_huffhines]

G-L-O-R-I-A

 

[Quaint88]

Another thing to look at is the resolution of the 7th (B flat) to the 3rd (A) of the next chord. It’s taught in jazz and blues.
Soloing over Standards and Jazz Blues with "Functional Harmony” - METRONOME ONLINE - free online metronome

Thanks for sharing that! It took me a little time to process it for the chord progression, but the voice leading from 7th to 3rd (or the 7th becoming the 3rd) is in a lot of the changes. I charted it out (the alternating colors are just so you can tell what goes with what).

 

[RiverVol]

Thanks for sharing that! It took me a little time to process it for the chord progression, but the voice leading from 7th to 3rd (or the 7th becoming the 3rd) is in a lot of the changes. I charted it out (the alternating colors are just so you can tell what goes with what).

View attachment 249416

Good work on the chart - take a look at your 7ths. It may help to grey out the 7ths that you don't include in a chord - otherwise, in your example, you have either a maj7 or Dominant 7 chord on every instance. All natural 7s are 1/2 step below the root - unless you specify b7 (flat 7) - which is a whole step below the root - which gives you a dominant seventh chord. ie... D - F# - A - C# = Dmaj7 • D- F# - A - C = D7 (or dominant 7) Normal triads (many chords in many songs) don't have a 7th.

I'm sure you know this, but it may help to distinguish chord types as you study.

Also, if you haven't googled circle of fifths, go ahead and give it a whirl. - makes the commercial music world go 'round.

 

[Matt2496]

Another thing to look at is the resolution of the 7th (B flat) to the 3rd (A) of the next chord. It’s taught in jazz and blues.
Soloing over Standards and Jazz Blues with "Functional Harmony” - METRONOME ONLINE - free online metronome

That's also the beauty of II V I's in jazz: the chromatic movement of the 3rd and 7th chord tones during chord changes. Said chromatic movement helps alot during improvisation.

 

[Quaint88]

G-L-O-R-I-A

That's a good one with a very common chord progression: E, D, A repeatedly, which I believe is V, IV, I (someone correct me if I'm oversimplifying here). I think the voice leading is what makes this one sound good (the way the individual notes in the chords are only a whole step or half step apart from those of the next chord in the progression). I charted it out wrapping back around to the E.

 

[Quaint88]

Good work on the chart - take a look at your 7ths. It may help to grey out the 7ths that you don't include in a chord - otherwise, in your example, you have either a maj7 or Dominant 7 chord on every instance. All natural 7s are 1/2 step below the root - unless you specify b7 (flat 7) - which is a whole step below the root - which gives you a dominant seventh chord. ie... D - F# - A - C# = Dmaj7 • D- F# - A - C = D7 (or dominant 7) Normal triads (many chords in many songs) don't have a 7th.

I'm sure you know this, but it may help to distinguish chord types as you study.

Also, if you haven't googled circle of fifths, go ahead and give it a whirl. - makes the commercial music world go 'round.

Thanks! Yes, you're correct that we don't play the major 7th chords. I was mainly interested in seeing how well the 7th to 3rd idea held up over the chord progression at hand. Also, the only class I ever took involving music theory was jazz band, so I'm used to including the 7th's in my thinking (we had to, of course).

 

[Chris4Vols22]

That's a good one with a very common chord progression: E, D, A repeatedly, which I believe is V, IV, I (someone correct me if I'm oversimplifying here). I think the voice leading is what makes this one sound good (the way the individual notes in the chords are only a whole step or half step apart from those of the next chord in the progression). I charted it out wrapping back around to the E.

View attachment 249422

Again without listening, I think a more accurate description of this progression is E-Mixolydian, not so much A-major. If it starts and ends on E, and E feels like a "tonic" of sorts, that's modal. Fifth mode of the major scale is Mixolydian.

 

[Chris4Vols22]

That's the same thing I have (except I mistakenly thought the use of the secondary dominant meant a key change instead of tonicism).

I think those are the most interesting parts of that chord progression, but do you see any others before I move on to another?

If we're being very nitpicky, "tonicism" isn't the best word for this example; it's just use of secondary dominants.

You're definitely right, those are the most interesting moments in this example.

 

[Quaint88]

Again without listening, I think a more accurate description of this progression is E-Mixolydian, not so much A-major. If it starts and ends on E, and E feels like a "tonic" of sorts, that's modal. Fifth mode of the major scale is Mixolydian.

I get what you're saying about the progression being based in E Mixolydian, but could I still say it's V, IV, I (where the V is E Mixolydian, the IV is D Lydian, and the I is A Ionian)? Maybe that's not the right question, but I feel like I'm missing something here.

 

[Chris4Vols22]

I get what you're saying about the progression being based in E Mixolydian, but could I still say it's V, IV, I (where the V is E Mixolydian, the IV is D Lydian, and the I is C Ionian)? Maybe that's not the right question, but I feel like I'm missing something here.

You could say those things, and the chord spellings would line up perfectly with those designations, but they don't accurately reflect the function of the chords. It gets a little murky applying Roman numeral analysis to modal pieces because modes don't really lend themselves to have functions like dominant, predominant, etc. The tonic definitely functions the same way in both keys and modes, so it's a matter of figuring out what that is. That progression starts and ends on E and contains A and D as well, so it's obviously related to A major, but it's pretty clear IMO that A is not the "tonic," and E is.

 

[Matt2496]

You could say those things, and the chord spellings would line up perfectly with those designations, but they don't accurately reflect the function of the chords. It gets a little murky applying Roman numeral analysis to modal pieces because modes don't really lend themselves to have functions like dominant, predominant, etc. The tonic definitely functions the same way in both keys and modes, so it's a matter of figuring out what that is. That progression starts and ends on E and contains A and D as well, so it's obviously related to A major, but it's pretty clear IMO that A is not the "tonic," and E is.

There are loads of bluegrass songs just like this. Many songs will start on A, then go to G, and then D. On the surface, this looks like D major, but when you actually listen to the song, the starting and ending chords, it screams key of A. And of course, A mixolydian with its flatted 7th would be quite useful for improv.

Furthermore, not many songs start and end on a V chord.

 

[Quaint88]

You could say those things, and the chord spellings would line up perfectly with those designations, but they don't accurately reflect the function of the chords. It gets a little murky applying Roman numeral analysis to modal pieces because modes don't really lend themselves to have functions like dominant, predominant, etc. The tonic definitely functions the same way in both keys and modes, so it's a matter of figuring out what that is. That progression starts and ends on E and contains A and D as well, so it's obviously related to A major, but it's pretty clear IMO that A is not the "tonic," and E is.

Thanks for explaining that. So, describing the chord progression as V, IV, I implies that the root of the I is the tonic, which is inaccurate here because it's actually the root of the V. What would be a better way to notate the chord progression for modal pieces (a link is fine if it's a lot to explain)?

ETA: I7, bVII, V/bVII? That would accurately identify the tonic.