Sixth Chords

And Their Secret Identities

Is there really such a thing as a sixth chord? Isn’t it really just a first inversion minor seventh? A C6, for example, is indeed an Am7. In western classical music theory, deriving from figured-bass terminology, what is called sixth chord is a chord in first inversion with the root voiced a major sixth above the bass note. If this is done with an Am triad the result will be a C6.

In the standard jazz repertoire a 6th chord is often used as the tonic chord of the composition because it appears to sound more static or resolved than a maj7. Play a II-V-I with the I being C6 (Dm7 / G7 / C6) and you can clearly hear that C is the root of the C6 chord and it does not appear to resolve to the A note (which would make it sound like an Am7/C).

None-the-less, sixth chords fit the definition of added-note chords. It seems counter-productive to use the symbol C(add6) since the symbol C6 is so universal, but it's important to conceive of it as an added-note chord. When it comes to the less common altered 6 chords - b6 and the more rare #6, it makes sense to use the symbols C(add b6) and C(add#6) as well as Cm(add b6), etc.

Also a triad with a b6 added contains the identical notes as a first inversion maj7 chord with b6 that was added to the triad as root, i.e., Cm(add b6) = Abmaj7/C. Again, it is context that determines the root. If the sound of a minor triad is established, adding a b6 sounds like a m(add b6). A good example of this is Gary Peacock’s composition Vignette, which is both on Peacock’s album Tales of Another and on the Marcin Wasilewski Trio’s recording January. Both recordings are on the ECM Records label. There is a figure, repeated in different keys, with a minor triad with an added 2nd alternating with a m(add b6).

The listing below of sixth chords are arranged in the following manner:
Sixth chords (R356, etc.) from their scale position
Symbol (C6, etc.) Name
"Secret Identity” or enharmonic equivalent

What becomes blatantly obvious is that a sixth chords, all types of sixth chords are also some kind of seventh chord, usually if you use the sixth as root (C6 = Am7), though in a few cases even as the root (C(add#6) = C7).

Next: Seventh Chords

Copyright © 1993-2010 Jack DeSalvo