Use of the third

What do you know about harmonics?

Follow this rule and you will never go wrong. Doublings are octave, fifth, and if truly desperate, the third of a chord (see deceptive cadence resolution)

Thanks, but in the deceptive cadence (V-VI) why can the third be doubled?

...you try to solve it without doubling the third

Doubling the third is better than fifths or octaves, so for the benefit of the voice leading, a doubling that isn't exactly exceptional is accepted.

I can't understand, I can play the notes of the V for example of C Major (G - C - G - E) and then the notes of the VI (A - E - A - C or A - E - C - A) without doubling the third

l'only thing I will have wrong in the first is a parallel octave between bass and alto

Attention, the V as you have placed it (Sol - Do - Sol - MI), is actually a second inversion of the first degree of C Major.

Sorry, it would have been more correct to say: what you intended as the V degree is actually a second inversion of the I degree of C Major.

true, then G - D - G - B which goes up to A - E - A - C

even if it is full of parallel octaves :-)

but basically when is it permitted to double the third? in what circumstances?

Fox wrote:

but basically when is it permitted to double the third? in what circumstances?

Sorry, but it's not like there is a decalogue of rules. There are priorities and, as I already explained to you, the choice of doublings follows the rules of harmonics. The third is doubled as little as possible except where avoiding doubling worsens the voice leading. If you want to play it safe, double the fundamental or at most the fifth.

So this is the rule! You have to know when it's worth it and choose. The deceptive cadence is the most evident case where doubling the third is preferred. It is a clear rule only because if you try to resolve a deceptive cadence without doubling the third, you end up with pathetic voice leading or fifths or octaves. ... so you know it a priori. In other cases, you have to choose for yourself ... "if it is the lesser evil"

Now I understand well! everything is very clear

thank you so much!

There are degrees in which the third is doubled much more than the root or the fifth.

For example:

- with a 4 in the bass, it is more common to double the bass using a 3 and a 6: one can eventually debate whether the resulting chord is a II in first inversion or a IV with the sixth; a particular case of this is the Neapolitan sixth;

- with a 2-3 bass motion, using a V seventh, the I in first inversion will have two thirds and is perfectly "regular";

- in a 6 moving to a 7, a IV in first inversion with the double third is commonly used.

If one wants to establish a rule, the third is doubled if the two voices (which form the third) move by contrary motion and by step.

To read something on the subject, in De la Motte's Manual of Harmony, chap. 5 par. 2, this exact matter is discussed.

Thank you, it's interesting; I will get the De la Motte manual which I have already heard of. At the moment I am studying with Walter Piston's, which is well-made but not suitable, in my opinion, for beginners like me, but rather for students who already have good foundations in harmony..

I knew anyway that the third can be doubled on certain occasions and is absolutely forbidden in others; one just needs to know when and why it must be avoided and vice versa.

I still haven't quite understood when I can use the doubling of the third, even while reading what you wrote, which is undoubtedly well-written; the fact is that I have many gaps and some things I don't grasp immediately

I find it very interesting, and also instructive, to reread the "old" discussions every now and then, like this one from July 24-25, 2015.

Fox wrote that he was studying Walter Piston's manual, knowing that the third can be doubled on certain occasions, but not knowing which ones.

Yet Piston seems very clear and practical to me in this regard.

On page 68 of the Italian edition it says:

"The usual procedure for doubling triads in first inversion can be summarized as follows:

a) the bass of the triad in first inversion is doubled (not therefore the root) if it is a strong degree of the scale (the I, the IV, or the V, sometimes the II);

b) if the bass is not a strong degree, it is not doubled, but a strong degree present in the chord is doubled."

Good Harmony.

You are absolutely right Boesendorfer, probably a book (or n books) is not enough to make a composer

Fox wrote:

On 24/7/2015 at 12:36, Fox said:

Hi everyone

Sorry, I didn't quite understand in which cases the third can be doubled and when it is instead forbidden

could someone please explain it to me?

thanks a lot

Hi!

There is no fixed rule: theoretically, it is only allowed in the deceptive cadence ( V - VI ).

In reality, I can tell you that, analyzing Bach's chorales, you sometimes find doubled thirds that don't cause any offense at all.

Bach makes this choice to maintain beautiful, fluid, and singable lines, given that these are, as it happens, chorales (of course, it's not like you'll find 5 doubled thirds in a row).

As Dante rightly advised you, you have to evaluate case by case: the doubled third is fine if it is the lesser evil (avoids parallel octaves and fifths unless you are writing a piano accompaniment --> Murky's bass).

Have fun