Diatonic Quadad Analysis

It's time to analyze Quadad Chords just like we did with Triads.


View the full lesson at Diatonic Quadad Analysis | JustinGuitar

Can we please have the answers to the exercise portion of this lesson where we are to write out the notes in the E Major Diatonic Quadads? I’m having trouble analyzing the notes in each chord to work out what chord type is on each scale degree. Specifically, dealing with the root notes as a sharp. Thanks!

1 Like

I think I just cracked the code

does it almost follow the Diatonic Chord Progression of Major-Minor-Minor-Major-Major-Minor-Diminished? but instead of that, it’d be Maj7-Min7-Min7-Maj7-7-Min7-Min7b5?

EDIT: I just got to the Diatonic Quadad Chord Progression and man do I feel smart

1 Like

Here is a clue …

Justin’s template

image

You are comparing the chord notes with the major scale of each chords root note.

E major scale = E, F#, G#, A, B, C#, D#

Quadad = E (1), G# (3), B (5), D# (7) = 1, 3, 5, 7 = maj7

F# major scale = F#, G#, A#, B, C#, D#, E#

Quadad = F# (1), A (b3), C# (5), E (b7) = 1, b3, 5, b7 = min7

From earluer lessons you should be able to complete the major scales for all root notes of the quadads and decide if the notes within the quadads match exactly or are modified (by flattening).

G# major scale =
A major scale =
B major scale =
C# major scale =
D# major scale =

I hope that helps.
:slight_smile:
Cheers
Richard

Yes indeed.
Smarty pants you are!
Have a gold star.
:slight_smile:

I got confused because of the page layout in ‘learn more’ . For the first four chords the text is adjacent to the relevant chord diagram. From the V chord on though, the text next to the chord diagram is for the previous chord. It just needs an adjustment to the layout.

1 Like

@netwiz Have you posted in the correct topic? I have looked from top to bottom of the learn more and there are no chord diagrams.

I used the wrong term but this is what I mean

The texts ‘ok so now we’ll look at the IV chord’
and
‘so the chord built from the 4th degree …’
both relate to the diagram under the first of those, knocking the rest of the text+diagram pairings out of sync.

The text ‘so the chord built from the 4th degree…’ is alongside a diagram for the V chord, and this mismatch continues.

Above these, the text always relates to the diagram that it is aligned with.

1 Like

@netwiz. got it. Thanks for clarifying. I have gone in and made edits to the layout and minor changes to the text format too. Hopefully it is easier to read and follow now.
Cheers :smiley:
| Richard | JustinGuitar Approved Teacher, Official Guide & Moderator

1 Like

When working out the key of E, the III chord consists of a G#, B, D#, and F#. When looking at the G# scale, we get a double sharp F, correct? And since the 7 (F#) in the III has just the ONE sharp, that would make our chord a G#min7, correct? That double sharp was really throwing me off! I’ll honest…it’s been so long since I had worked out the chords in key the “old fashioned way” that I had to Google the G# scale because that F## was throwing me off big time :pensive:

1 Like

You are absolutely right.

Certain keys have double sharps (A#, B#, D#, E# and G#) or double flats (Fb) and are therefore rarely used to compose music.

The key of Ab has the same (enharmonic) notes as G#, with a natural G instead of the F##. It’s easier to write music in Ab than in G#, but the latter exists because we need it for analysis, like the exercise you solved.

We need some kind of F in the G# scale, so we’re stuck with the ugly F##.

1 Like

Yes. Some keys are horrid and seldom used, if ever. A key like G# is more easily arrived at by taking all of the notes in the key of G and imagining them sharpened but keeping the same letter.

G, A, B, C, D, E, F#

G#, A#, B#, C#, D#, E#, F##

If you know some mathematics, you cold think of it a little like multiplying indices with the same base value. The base value stays constant, the index value increases by addition. For example:

image

Going from the key of D# to the key of D### (ridiculous but theoretically possible).

D# = D#, E#, F##. G#, A#, B#, C##

  • D# becomes D### (# + ## = ###)
  • E# becomes E### (same as D#)
  • F## becomes F#### (## + ## = ####)
  • G# becomes G### (same as D#)
  • A# becomes A### (same as D#)
  • B# becomes B### (same as D#)
  • C## becomes C#### (same as F##)

D### = D###, E###, F####. G###, A###, B###, C####

:scream:

1 Like