My main question is in the title above.

Chords in Common Practice Style only have three notes, so in 4-part harmony (SATB), one note will be repeated.

In music theory, there are a ton of doubling rules. I am wondering if there is an easy way to memorize all of them, because I don't want to always have to look back at my music theory book when writing chorales (I don't have to follow the rules, but I want to).

Here are the list of doubling rules:

  • Root position: Best double root
  • I, I 1st inversion, ii, IV: Best double root, 5th and 3rd acceptable
  • V: Best double root, 5th acceptable, 3rd unacceptable
  • viio: Best double 3rd, root and 5th unacceptable
  • vi: Best double 3rd, root acceptable, avoid 5th
  • VI: Best double 3rd, root and 5th unacceptable
  • I, IV, and V first inversions: Best double root (match in soprano), 5th acceptable, avoid 3rd (for I and IV first inversions), and 3rd unacceptable (for V first inversion)
  • ii, iii, iv, and vi first inversions: Best double 3rd, root acceptable, avoid 5th
  • 2nd inversions: Best double 5th, avoid root and 3rd, root and 3rd unacceptable in a cadential 6/4
  • V7 without 5th: Best double root, 3rd and 7th unacceptable
  • Augmented and diminished: Best double root, root unacceptable (for viio)
  • Altered chords: Altered note unacceptable
  • Scale degrees: Best double 1st, 4th, and 5th; 2nd, 3rd, and 6th acceptable; 7th unacceptable
  • Root and 3rd only: Best triple root

That is seriously a ton of stuff.

Any help will be appreciated. Thanks.

  • 3
    Just a small correction, chords in common-practice music are not necessarily three notes, there are plenty of seventh chords, augmented sixths, etc. with 4. Triads only have three pitches. I'm actually not terribly sure what you about "doubling rules" here. The only rules I can think of are that you shouldn't double tendency tones, which isn't terribly hard to remember. Root-position triads tend to have doubled roots, first inversion triads are fairly free, second inversion usually double the fifth—but those aren't rules so much as tendencies. Could you give some examples of what you mean? Jul 11, 2014 at 2:48
  • At least my music theory book shows that you double 7th chords without the 5th.
    – user8886
    Jul 11, 2014 at 5:09
  • 2
    I've often heard people say to avoid doubling the third in general. You should also avoid doubling a tone that by the mechanism of some other voice leading requirement would have to resolve in a certain way. For instance, doubling the third of the V chord would probably be bad because the leading tone should resolve up by half-step, and that would result in parallel octaves. I'm no expert though.
    – Grey
    Jul 11, 2014 at 6:44
  • @Grey Yeah, that's what "don't double tendency tones" means. System Security, you can leave out the fifth of a seventh chord if you need to, but they are just as common if not more common with all four notes. Jul 11, 2014 at 13:04
  • 1
    why don't they teach: don't double when it sounds bad! and then explain and teach what is bad, so that we hear that it is bad. And then nobody wouldn't need to learn any rules. ;) Apr 6, 2019 at 8:17

5 Answers 5


My Music Theory professor pretty much distilled it to 3 bullet points of do's and dont's

  • Don't: Ever double tendency tones (notes that must resolve a certain way like the leading tone, notes outside the key, and chordal 7ths)
  • Do: Seek to double the tonic, subdominant, and dominant (1, 4 and 5)
  • Do: If not possible , seek to double the root of the chord.

Never violate the don't and try to do the others whenever possible.

  • Most of the texts I've worked with discuss best doubling practices in terms of what inversion the chord is in. Doubling the root of a second inversion chord, for instance, is usually best avoided, contra bullet point 3. I'm curious about how the second rule worked in practice. So if I had a root-position ii chord, I should probably aim to double the 3rd because it's the subdominant? Kostka/Payne, for example, would consider than to be acceptable, but far inferior to doubling the root. Jul 11, 2014 at 13:27
  • @PatMuchmore Yep. And I wouldn't call this a perfect system as there are always exceptions including the two you pointed out (even though in a second inversion chord I would consider the root and 3rd tendency tones due to the dissonance in a chord in second inversion). What I like about it is it is simple and it gives an idea of all the rules without drilling down into each of them.
    – Dom
    Jul 11, 2014 at 16:31
  • Interesting. Although I get where you're coming from on the tendency tone idea, I'd hesitate to describe the root and third of a 6/4 chord in that way since their direction of resolution is determined by context. For example, although they both generally resolve down in a cadential 6/4, one resolves up and the other holds a common tone in the passing 6/4 between IV and IV6. I'm just trying to think of a case where doubling the subdominant or dominant in a chord (wherein they aren't already the root) is superior. Do you know what text your instructor was using? Jul 11, 2014 at 16:58
  • @PatMuchmore “Music in Theory and Practice”, 8ed, by Bruce Benward and Marilyn Saker – ISBN: 9780073101873. Sorry it took so long I had to dig up the syllabus for the class.
    – Dom
    Jul 21, 2014 at 20:16

This is not a question that lends itself to one definitive answer. There are certain methods where there are differences in thought. I can tell you what I was taught, but it would be better to ask the person who is in charge of your exams to give you clarity on what he/she wants.

Here are some general principles:

  • Primary Chords: Double the root
  • Secondary Chords: Double the third
  • First Inversion (Major): Double the root or fifth
  • First Inversion (minor): Double the third
  • Second Inversion: Double the fifth
  • Augmented and Diminished: Double the third
  • Never double leading tones.

The classical way of thinking is if you would jump to a note that is part of the chord (eg. on the down beat), then you would have to change another note in the chord to keep the doubling correct. However, ABRSM wants the correct doubling on the strong part of the beat. They then allow you to do the decorations afterwards (even if that affects the doubling)


What I have learned as common basis of most of the rules are several "low-level" things as follows:

  1. Doubling leading tone must be avoided as it would lead to octave parallelism (both leading tones must be led to the tonic).

  2. Avoiding doubling the root in second inversion is caused by the fact that root forms 4th with bass and being a dissonance in this case (in common practice harmony) must be resolved. So, both resolving 4ths cause parallelism.

  3. Avoiding doubling 3rd in first inversion of major triad lays in the area of overtones.

    a) As we know, the 5th overtone is major 3rd of the original tone.

    b) Doubling a tone also amplifies its harmonics.

    This two facts leads to amplifying the major 3rd TONE of the bass. But for major chord we have minor 3rd above the first 3rd - 5th of the chord. As a result we get a half-tone dissonant interval between normal 5th (of chord and "#5th" from overtone. For the first inversion of minor chord the 5th overtone of bass is the same TONE as 5th of the chord because both of them are major 3rds of 3rd of the chord.

As you can see this basic "laws" explain plenty of high-order rules. And I guess there must be other similar laws in area of voice leading and overtones that lay underneath of "ton" of doubling rules.


isn't the summary of all rules finally:

  • don't double the leading-tones in of the dominant 7 and secondary dominants (= tendency tones! and augmented 5th)
  • don't double the bass tone of the 6th chord (the 3rd) -exception VII6

in all other cases just do what you like!

priorities: root of I,IV,V, (which are same tones as 3rd in related chords vi,ii,v)

the fifth and 3rd are also available

always regarding the chord progression!


I think Walter Piston gave the simplest direction.

  • Root position: double the root in root position
  • 1st inversion: double a tonal degree (^1, ^4, or ^5) the concern of the doubling then is clarity of the key, the tonality, via the emphasis of tonal degrees.
  • 2nd inversion: double the 5th of the chord - i.e. double the bass tone. Here the focus seems to be contrapuntal with cadential and auxillary 6/4 chord being considered decorative movements around root position chords, and the passing 6/4 potentially just not a proper chord.

Add to those the general rule:

  • don't double tendency tones (because if the two doubled voices move according to tendency parallel octaves will result.)

The subdominant degree ^4 seems to provide a nice case to illustrate. In V6/5 the chord's seventh is degree ^4 (a tonal degree that could be doubled in a first inversion chord) but as the seventh of a dominant seventh chord it's a tendency tone, so don't double it.

The tendency tone rule seems to trump the other rules.

Put all together and there seems to be two primary concerns:

  • make the tonality clear
  • good voice leading

If those two reasons for various doubling rules are understood first, then maybe the details of the rules will be easier to remember.

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