Tuesday, May 6, 2008

minb6 chords?

Q: I'm thinking about 6th chords. I know that a 6th chord, whether it is minor or major (depending on the 3rd of the chord), ALWAYS has a major 6th interval. So, taking the min 6th chord, I can see from what you said in your lessons that it can only replace a ii chord since out of all the minor chords of the scale (ii, iii, vi), only the ii has a major 6th interval.

I also understand this about the ii chord because I understand that the dorian mode is a minor scale with a raised 6th (raising it to a major 6th interval). But what about the iii, and vi? Suppose I wanted to play some kind of 6th chord for each of them where the 6th interval is minor to keep the chords diatonic? So, for lack of better nomenclature, I'd be playing a minor b6 chord. But... there doesn't seem to be any such thing as a minor b6.

Are "minor b6" chords simply not played in favor of some kind of 13th substitution for the iii, vi chords? I guess I came across this confusion because I had attempted to write down and play the C major scale harmonized with each note's appropriate triad and its 6th interval. That would have been C6, Dmin6,..... Emin b6??? (no such thing), F6, etc.... It looks to me that a 6th chord harmonization is kind of out of the question. Is there an actual chord that includes only a minor triad and a minor 6th in western music theory?

A: Great question. Yes, there is a minb6 chord, sometimes it (mistakenly) gets written as a min#5 chord as well. Usually the chord contains a b7 as well, if so, technically we should call it a min7b13 chord. A good example of a tune would be that Steely Dan tune, (I don't remember the name or key of the tune but you'll get the idea:

     C69 - Bmin7b13


This pattern keeps getting moved around. It looks like a IV-iii thing to me.
Also you get it like this: Amin7-Amin7b13-Amin13. Just play your garden variety Amin7 chord on the 5th fret and keep moving the note on the 2nd string up chromatically. You see this in the song "Israel" in the real book.


The chord works fine in a diatonic progression. Here is a nice voicing (also at the top of this page):



Play this shape from the second fret over an open 6 string for an Emin9 to the one on the 7th fret for a Emin7b13 chord. It is a nice sound, you will be playing E aolian here. I use this kind of thing in "Little Wing" for example.