In a minor II-V-I progression, we usually have a IIm7(b5) chord followed by a V7(b9,b13) chord, resolving into Im7. I always thought the diminished 5th in the II chord (also the minor 9th in the V7 chord, same note) was like a "hint" that a minor chord was coming, since it corresponds to the minor 6th of the I chord. That would be F in A minor/C major.

If you analyze the progression from a relative major standpoint:

VIIm7(b5) _ V7/VI(b9,b13) -> VIm7

In a major harmony, the VIm7 is related to the Aeolian mode and should have a minor 6th, right?

However, it came to my attention that some standards, like Autumn Leaves and Caravan (no II here, but a long time spent on V7b9), have this chord written and played as Im6 sometimes, with a major 6th instead. Is there a particular reason for this?

Edit: Is this a chord substitution? Some substitutions are based in harmonic concepts, like the tritone substitution. Does this major 6th thing have such an underlying concept?

  • Which chord is Im6 in Autumn Leaves? I've seen many different music sheets for the song, but never once seen a m6 chord there; it isn't on the real book either. Ι've never seen any major 6th chord either there. But if you saw a I6, it is a common substitution for Imaj7 Commented Mar 7, 2015 at 0:00
  • Em6 in G major versions, last chord of it's A section. Please note that it's Im6 in minor harmony (VIm6 in a major key like Autumn Leaves). youtube.com/watch?v=KoxY_xPmJXg
    – Costagero
    Commented Mar 7, 2015 at 0:06
  • So, your question is why is there a C in the E minor chord? Commented Mar 7, 2015 at 0:10
  • 1
    A minor 6th chord is spelled 1 b3 5 6 which with a root of E is E G B C#. It's like any other substitution in Jazz it's function is similar, but the flavor is different.
    – Dom
    Commented Mar 7, 2015 at 0:20
  • 1
    I don't understand the downvote. This is a very relevant question.
    – Matt L.
    Commented Mar 7, 2015 at 11:06

2 Answers 2


You are right that in minor the minor sixth of the key is part of the II chord, and it is a tension (b9) that is very often used on the V chord. However, it is not a valid tension on the I chord, because the minor sixth is an avoid note on that chord (basically because it is a half step above a basic chord tone, the 5). In this blog post you can read more about avoid notes.

On the other hand, the major sixth is a valid tension on the I chord in minor. A minor 6 chord always contains the major sixth. It comes from the melodic minor scale. The I chord in minor comes in three basic flavors: Im6 (with a major 6th), Im7 (with a minor 7th), and Im maj7 (with a major 7th). The corresponding chord scales are melodic minor (for Im6 and Im maj7), and dorian (for Im7).

  • The linked blog post is an outstanding resource. It might be worth mentioning that a I min6 chord doesn't require melodic minor. Dorian can also be used over a I min6 chord.
    – jdjazz
    Commented Jun 11, 2017 at 23:11
  • @jdjazz: Thanks! ( I wrote that post :) And indeed, of course a minor 6th chord doesn't require anything, it's just that melodic minor is the most common and most natural choice, because it has no avoid notes when played over a m6 chord. Dorian contains all chord tones as well, but its 7th degree is an avoid note over that chord because it is a half step above the 6th. Melodic minor and dorian relate to a m6 chord a bit like Dorian and Aeolian to a m7 chord: both are possible but one is more natural because of the lack of an avoid note.
    – Matt L.
    Commented Jun 12, 2017 at 7:44

I think the answer to your overarching question is: there's no requirement that the ii chord or the V chord share the same scale/chord tones as the i chord. The ii-V-i progression will still sound good even whether or not a common scale is used across all three chords.

For example, it's not uncommon to play a Locrian ♯2 scale over the ii chord, an altered scale over the V chord, and then a melodic minor scale over the i chord. If you take a ii-V-i in G min, this would be equivalent to playing these chords and scales, respectively:

| Aø7 | D7alt | Gmin | Gmin |

| C melodic minor | E♭ melodic minor | G melodic minor | G melodic minor |

There are plenty of notes that aren't shared across these three scales, but those scales nonetheless sound good over the ii-V-i.

That said, there might be reasons for choosing to play Aeolian vs. Dorian vs. melodic minor over the i chord. Matt L. mentions one possible reason for choosing dorian over Aeolian--because Dorian has fewer avoid tones. On the other hand, one might choose Aeolian for continuity with the V alt chord, as you suggest in your original post. Another factor one could consider when choosing a scale is the melody--if the melody uses a ♭6th over the i min chord, then maybe the solos should too. But there is no prescribed scale and the soloist often has freedom to choose which to use. So the Aeolian can be a great sound even despite its ♭6 avoid tone, but there's no rule that Aeolian is required over the i min chord to create continuity with the iiø or V7alt chords.

A couple notes:

A i min6 chord is extremely common on Autumn Leaves, in large part thanks to Miles Davis, who in bar 7 plays the natural 6th in the melody instead of the root. (This link starts after the intro, and the natural 6th is heard at 1:06.)

Playing i min6 instead of i min7 doesn't qualify as a substitution because we're playing the same chord, just with different alterations.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.