For a given chord, the chord tones are composed via going 3rd, like a C Major is a {Major 3rd, Minor 3rd} or a C Minor is {Minor 3rd, Major 3rd}. The 7th, 9th, 11th, and etc... are also created via stacking 3rds.

It seems to me that going with 3rds, up or down, can't go wrong.

When I tried to write a harmony line for a vocal melodic line, I noticed that if I go 3rd intervals up, the melody remains intact. It is recognizable to most people. It just becomes fatter and warmer in tone.

However, if I go 3rd intervals down, the melody becomes different. It just doesn't sound like the original melody anymore.

Here's a concrete example, this is Ode to Joy in C (not sure if it is 100% correct, just did it from memory)

3rd Interval up

The melody is recognizable, it didn't change the quality of the original song. However when I do the opposite, instead of harmonizing E with G, I harmonized it with C (3rd interval down), the quality changed! It sounded like the harmony hijacked the melody.

Here's my problem. I have a female singer who sings the melody. I want to add a male voice to it to thicken the tone. The male cannot reach 3rd interval above the female. What should the male part do to support the melody? Go 3rd interval up and then down an octave?

Thank you

  • 4
    Going to the 6th below is pretty common, indeed. Jan 22, 2021 at 0:10
  • 1
    When I tried singing the "3rd up" melody alone, I got a bizarre feeling from it, as if it was half unrecognizable and I was trying to sing something in the Phrygian mode instead of a major key-like mode.
    – Dekkadeci
    Jan 22, 2021 at 13:29

7 Answers 7


In short: because good melodies try to implicate a harmonic progression even when sung or played without any accompaniment, they are bound to contain chord root notes in critical points in time. Since chords are built from thirds above roots, you have to place your harmony notes above the melody, in order to produce the chordal harmony implied by the melody in those critical places.

No static interval is guaranteed to always support the harmony appropriately. But I agree that on average, in actual songs, a third above or sixth below the melody tends to work more often than a constant third below or sixth above.

I don't have any statistical evidence, but based on my own experience, the problem with third-below harmony is that the melodies of songs tend to use notes which, if harmonized with a third below, will produce a harmony which does not support the melody's intent at that point. This is because of how melodies tend to be written. Many good melodies work stand-alone, so that the original intended harmony gets across even without any supporting harmony notes.

Since Western chordal harmony is thought to be built from thirds - even if voiced in different octaves - an interval's being a third cannot be the problem in itself. Thirds are not the problem. Harmony is full of thirds. But which thirds do you select - if you select the wrong thirds, you get the wrong harmony.

Therefore the only remaining variable are the melody notes, and where they tend to be in actual songs. At least the tonic note seems to be used quite a lot in actual melodies, particularly in the ends of lines/parts, and there the song attempts to get a "home" feeling. If you harmonize the tonic note with a third below, the result will not be the tonic chord. The melody desperately tries to get home, but your vocal harmony spoils the attempt.

For example, if the song is in A minor and the song wants to end on a tonic chord, a third below - assuming A natural minor scale - will produce an F - A interval. This produces a sensation of NOT being home and NOT being at rest. Many songs want to end! If you want to create perpetual motion music, where all attempts to end are voided, then by all means, harmonize with a third below.

  • Another way of looking at things would be to observe that for most melody notes, either the note a third below or the note a fourth below will usually fit the underlying harmony, but in most cases where one works, the other won't (sometimes both may work, e.g. in C major, if an F melody note sits atop a Dm7, the chord will contain the notes a third and a fourth below the melody).
    – supercat
    Jan 22, 2021 at 22:39

'Ode To Joy' SORT of works with 3rds above, though a maj7 chord on the third note isn't quite what Beethoven intended! The more usual harmonisation starts off with 3rds below, though this soon needs to be modified so as not to mangle the intended harmony.

enter image description here

That's the trouble with trying to stick to either 3rds above or below. It works for a bit, then you have to switch to the other one, or do something else completely.

I expect you listened (with a sigh of relief) to this tune being sung today - though Lady GaGa took it in 4/4 with a few extra beats thrown in now and again. Neither constant 3rds over or under are going to be much use, you really need to hit notes that fits the chord, on the main beats at least.

enter image description here

  • 2
    The "Star-Spangled Banner" begins with 5–3–1, no?
    – Richard
    Jan 22, 2021 at 15:18
  • 1
    True. I don't know it that well :-)
    – Laurence
    Jan 23, 2021 at 0:17

We tend to hear the lower note as the more stable tone. So, all things being equal, it would be perceived as the root -- or at least the more important note -- of the corresponding chord. Singing a third above, then, suggests a major or minor chord based on the melody note. Whereas singing a third below would make the harmony sound like the defining pitch.

A melody note of C with an E above it will suggest, say, C major. Singing a third below would tend to suggest A minor.

This is, obviously, a vast oversimplification, but in broad terms, that's why harmony in thirds works better above the melody than below.

  • 2
    I don't think the lower note being lower is really the relevant thing here. Jan 22, 2021 at 0:30
  • 2
    The argument about harmony is right, but about the relative pitch – no. Lower second voice often sounds great. A very typical example is female lead singer with a background male singer. Jan 22, 2021 at 0:41
  • Thanks for the answer and other comments. I still have the dilemma of how to harmonize if I have to go low (lower in pitch). What would be a good strategy for lower second voice? 6th down?
    – mofury
    Jan 22, 2021 at 1:04
  • @user1079505 Lower isn't a problem, but lower by a third can be.
    – Aaron
    Jan 22, 2021 at 1:18
  • 2
    @mofury Lower by a sixth is the same pitch as up a third, so it's a better bet. Ultimately though, you can't generally harmonize with the exact same interval throughout. As a starting point though, a sixth below is fine.
    – Aaron
    Jan 22, 2021 at 1:19

It seems to me that an easy and fundamental point is being (partially) missed until now: the relation of the degrees of the melody and of the harmonization in the existing underlying harmony.

When the melody plays a note of the harmony, with a third above the harmonization would lead to the seventh or ninth of the chord at most, all notes that are considered part of a chord extension. It wouldn't change the harmony that much (might be a bit off style, but that's it), and it probably will do exactly what the harmony is, by playing the third or fifth.

With the third below, it's much more possible that the harmony becomes destabilized: the tonic is a very common note in the melody, and the result is to have a third below, which is not a standard note in the harmony.

That's why playing the third below won't work well with your example, especially if the singers are accompanied: while for the most part it's ok (the melody starts on the third, the second voice will sing the tonic), when the melody goes to the tonic, the harmony of the Ode is generally again in the tonic harmony (in the symphony it's not always like that, but that's another story), but your male singer would sing a note that is completely off with that chord.
This will be bad at the end of the first 4 bars, and awful on the end of the phrase at the eight bar: A is definitely not in the C major chord (not in the time of Beethoven, at least).

Third harmonization is easy and intuitive, but must be used with care, no matter the direction. Usually, going a sixth below is the easiest trick when things don't sound very well (harmonically is almost the same as the third above), but choosing the right note might dramatically change the result, even if the note is in the chord (and even in the triad).

Depending on the chord, its role and the context, you might prefer a fourth, fifth or sixth above (all three common when the melody plays the fifth of the chord, but not only), or even the unison or octave (usually very powerful and effective for high pitched and long notes at the end of a section or the piece). Second and seventh intervals are more uncommon and often used as small temporary variations.

Generally speaking, if you have a note of the chord in the melody, go with another one in the same chord for the other voice and you'll be probably fine; besides that, use your ears, experiment to understand the differences and then start taking harmony lessons, which will explain all this much better ;-)

  • 1
    The usual way is to have a tonal line, write a third below except on the tonic, where you skip to the fourth below. That sounds far better to me than parallel thirds above (which hits the leading tone for not much reason). Beyond that you might as well actually write counterpoint.
    – user28245
    Jan 22, 2021 at 23:46

What you have to say about harmonizing above the melody sounding better than below is basically your opinion, which is fine, but can’t be subjectively answered. Music is art and we make our own esthetic choices when composing or arranging. Also, the fact is that good harmonization is not quite as simple as a 3rd up or down. Sometimes you have to break away and use another interval to make something sound good AND work with the harmony. Your “Ode to Joy” example would be considered objectionable by some since the melody is clearly on top in the symphony. The other issue is genre. In pop music it is more common to harmonize above the melody than below it so people with a pop sensibility will naturally prefer the upper harmony.

As for your musical situation, harmonized melodies need to be done on a case to case basis. Up a 3rd and down an octave is actually down a 6th, which might be a good starting point but many good harmony lines sometimes are a bit independent. They change intervals and weave to and away from the melody. Check out “If I Fell” by the Beatles, it’s a great example of this.

  • You have a very good point. I forgot about the context. Different type of listeners would form different opinions about what's "good". Do classical musicians and pop/rock musicians harmonize with big difference in approaches?
    – mofury
    Jan 22, 2021 at 1:25
  • I would say there are a lot of commonalities because they’re both largely based on tonal harmony but there are things that are done in rock/pop that are not typical to more traditional classical, such as parallel motion in 4ths and 5ths. Also your example of harmonizing a 3rd above is definitely much more common in pop/rock. Jan 22, 2021 at 2:14

For starters, singing a note a third above, for every note sung is not going to work in every, or many, songs.Those with the same tonic chord for several bars will allow it to sound o.k., but simply following the lead line in thirds, fourths, fifths or any 'parallel' interval is doomed to sound bad at some point. Sorry!

Singing underneath has worked for ever, but for reasons aired in the existing answers, it isn't recommended in thirds. Sixths below works as much as thirds above - it's the same note, an octave lower, so the same caveats as above apply.

Eventually, you'll be able to harmonise on the fly, but for the time being, a good move is to sing the song one word at a time, whilst playing the chords on guitar, or keys, and listen to which notes fit best. Then stick to them. Some will be a 6th under, some a 5th, or a 4th. There may even be some where a 3rd under actually does sound good !!

Then there's the point where the song might modulate. in key C, notes D and F sound good together - not always, but frequently. If the underlying harmony is a D major chord, moving usually to G, then that F will sound awful, not awesome. Sing F♯ though, and all will be well. Still a 3rd above/6th below, but fitting with the chord at that moment.


A thing that I found only in Aaron's post touched on the original question: If the melody is in C Major, going a 3rd up or a 6th down is like adding a melody in Phrygian scale, going a 3rd down is like adding a melody in Minor scale. Klezmer for example is based on the Phrygian dominant scale.

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