Piano World Home Page Forums Our Most Popular Forums Adult Beginners Forum Classical Sonata Analysis

Not sure where I got the Db from ... darn.

Now I would just call it Bb/E

I'm going stir crazy over here looking at this

Silly question. I'm looking at the chords now in this section. I am trying to be a good student, after all.

But, how are knowing the chords going to help me with understanding the key?

I suspect it has to do with the post yesterday by PS88 of what chords belong in a key. Is this on the right track?

I see you've got the D now not Db. Let me just erase that three page explanation!




I thought you were being humorous yesterday! Yes, that's precisely how it will help determine key. I thought we covered that back with the Moonlight - it must have slipped through with the furore of cross posting.

Hang on, another post to follow!

No, I really thought it was clever and had not thought about in this light before.

I thought we went over this before, Richard. About my fooling around and all. If in doubt, I am usually being serious.

If you take a major scale and build a triad on any of it's seven degrees using two successive thirds you will form the seven primary chords of the key.

Note that western harmony is all built on thirds (alternate notes).

Because of the major scale pattern T T S T T T S you will always have a major chord on degrees 1, 4 and 5, forming the I, IV, and V chords.

On the second, third and sixth degrees you will always have minor chords, II, III, and VI.

On the seventh step you will always have a diminished chord forming the very tritone that is used in the dominant seventh chord from the fifth step.

Adding another third to each triad will form the secondary sevenths using notes 1,3,5 and 7 from each degree. On degrees 1 and 4 you will always have a major seventh (major third, minor third, major third). On degrees 2, 3 and 6 you will always get a minor seventh (minor third, major third, minor third).

On the fifth degree, the dominant, you will get a unique seventh (major third, minor third, minor third) which we call a dominant seventh (after the degree).

On the seventh degree you will get a half-diminished chord (minor third, minor third, major third).

So in C major the seven primary chords are:
C major, D minor, E minor, F major, G major, A minor, B diminished

Note that a minor is the relative minor of C major, D minor is the relative minor of F major and E minor is the relative minor of G major.

Now rewrite these chords in this order:

F major, C major, G major
D minor, A minor, E minor

Now compare that with a diagram of the circle of fifths.

Write the B diminished above the G major and add them together to form the dominant seventh. That's how Gary gets the rootless dominant 7b9 from a diminished seventh or a rootless dominant seventh from a simple diminshed triad.

Herein lies the problem. I am always the other way. If in doubt, the joke went over your head!

That is lovely! I'd never noticed that before. It's a quarter of the circle of fifths, with major keys on the outside (or top, typed here) and relative minor keys on the inside (or bottom, typed here). These are also all the "nearby" keys for changing key one accidental at a time from the original key.

Rewriting with roman numerals, which helps me see the general pattern:


So it shows that each of the primary chords of a key, except for VIIdim, can become the I or Im chord of a nearby key.

Does this show substitutes also? So IIm can substitute for IV, VIm can substitute for I, and IIIm can substitute for V? Also VIIdim can substitute for V?

This is good stuff, for me. Still need to think more on the final exercise, but the wheels are churning.



It is unique that we call it a dominant 7th? Otherwise, looks like and everyday 7th?



Acknowledged. I will attempt to pace myself accordingly.

Yes, all relative majors/minors are only one note different.

The pattern, major third, minor third, minor third is unique to the dominant/5th degree so we call it a dominant seventh (or just a plain seventh as opposed to a major seventh or minor seventh).

All clear on the circle of 5ths, but not clear on what you mean by adding Bdim to G major to form the dominant 7th.

If you take the notes of the G major triad (G B D) and add the notes of the B diminished triad (B D F), then you get G B D F, which are the notes of G7, the G dominant seventh chord.

I'm glad you asked, because I didn't understand that either the first time I read it. It was only when you asked, using slightly different language, that it suddenly made sense to me.

I see, thanks. Oddly enough, I was actually doing this, but nothing was registering.

On the 7th degree we have a diminished. When we add the 3rd above (will always be major third above) we have a half diminished. Is there a preference thus, in calling this xm7b5 vs. half diminished?

Sorry, need to run now. Wiffy coming home from England this weekend ... yikes. Back in a few ...

m7b5 is the 'symbol' for a half diminished chord as 7 is the symbol for a dominant seventh.

We add a third by taking alternate notes from the scale. We may end up with a major or a minor third depending on the starting note.

The third above the diminished chord on the seventh degree will always be a major third above when in a major key.

The chord can either be called "half-diminished" or "minor 7 flat 5". There are two possible notations. One notation uses a circle with a slash that ought to be a superscript, but sort of like this (except make the circle smaller and higher): Bø. The other uses m7b5, like this: Bm7b5.

I am glad that you wrote both parts. There is a major trap in the theory books which I almost fell into myself. The form itself is as you wrote:
G(major third)B(minor third)D(minor third)F
in root position.
Or you can also see it as a major triad, where the "seventh" (F) is a minor 7 above the root G. In jazz or popular music where letter names for chords are used, it is commonly known as the "seventh chord". I prefer this in most cases, for a reason.

Dominant is one of the names of the degrees of a scale. These degrees are as follows: In a C major scale:
C - Tonic (the tone that is set; i.e. it's in C major)
D - Supertonic (means above the tonic)
E - Mediant (a third above)
F - Subdominant (it's under the dominant)
G - Dominant (It plays a major or dominant role. It is the second strongest note that the music wants to go to.)
A - Submediant (a third below)
B - Leading note (has a strong pull that "leads" to the Tonic. That's why in a G7 chord, the B tends to rise to C).

These are "functions" or roles which in simpler music tend to happen, or that we often see happening in music. It goes together with our I, IV, V Roman Numerals which point to functions.

Dominant seven refers to the "dominant" or V chord specifically which has the seven, and it usually leads to the tonic in our V7 progression. It uses all of the notes in the key for major keys. In minor keys, the third is raised (In C minor, the Bb is raised to Bnat so we still have G7 and not Gm7, to get V7-I = G7-Cm). The Dom7 happens to have the shape of *(major third)*B(minor third)*(minor third)* that Richard has mentioned.

In music we will often see a "seven chord" with that shape where it is not playing the role of "dominant" leading to the tonic. That is why that name presents a problem unless we've sorted that out. When I discovered this, I went back and checked in my theory books. They make sure to only show examples of seven chords functioning as dominants, going to I, so students never ask awkward questions. I was almost trapped into thinking that seven chords can only be dominants (V's), because that's all the theory books presented.

No worries here. I have been playing 7th's forever and only since joining the analysis threads in the last month or so, have paid much attention to what a dominant really was/meant.

This is all really good information. I'm printing out some notes from this recent thread activity as I think will help immensely in my understanding and better analysis moving forward. There is actually a lot to absorb here, when working through all the keys, and minor keys
everyone

I had learned to use the term "dominant seventh" if I need to be precise, regardless of whether it's functioning as V7 to I. This is so that the type of seventh chord which is "major triad plus minor seventh" has a name, just like all the other types of seventh chords:

major triad plus major seventh: major seventh chord
major triad plus minor seventh: dominant seventh chord
minor triad plus major seventh: minor major seventh chord
minor triad plus minor seventh: minor seventh chord
diminished triad plus minor seventh: half-diminished chord
diminished triad plus diminished seventh: diminished seventh chord

Perhaps I have been incorrect in learning this.

It does require accepting that a dominant seventh chord may be built (using accidentals) on a note which is not the dominant of the key you're in.

I have never thought of the 7th in terms of being major, minor or diminished above the root. Rather, and only as a major or minor 3rd above the triad

major triad plus major third: major seventh chord
major triad plus minor third: seventh chord
minor triad plus minor third: minor seventh chord
diminished triad plus major third: half diminished seventh chord
diminished triad plus minor third: diminished seventh chord

Is there anything incorrect with this? You may notice I did not include minor triad plus major 3rd. I do not think I have ever come across this. But, suppose it would be a minor major 7, although I would have probably called it something entirely different.

You have the intervals and names correct. I think it's useful to know the intervals from the root as well.

For example, dropping back to triads: a major triad can be thought of as a major third followed by a minor third. It can also be thought of as a major third and a perfect fifth above the root. It's the latter description which leads to us talking about "the fifth of a chord.". For example, "C7 without the fifth" is C E Bb, and you might want to describe that voicing.

Similarly for sevenths above the root.

I also find it easier to calculate a seventh -- 1-3 half-steps below the tonic (an octave up) than I find it to calculate a major or minor third above the fifth.