Naming Chords

[Scrybe]

I want to check I'm doing this right.

I just took a C major scale and listed each basic triad in it, then their extensions if harmonised solely from the major scale.

C D E F G A B C

Cmaj => C E G B D F A
Dmin => D F A C E G B
Emin => E G B D F A C
Fmaj => F A C E G B D
G7 => G B D F A C E
Amin => A C E G B D F
Bhalfdim => B D F A C E G

Then, I looked to see what intervals these extensions were against the root note of each chord. Am I right in thinking the following...

Emin has a b9 in the F note, and a b13 in the C note, so if writing this chord as a 9th, I'd write Eminb9 and, if written as a full extension, I'd write Eminb9b13

The Fmaj chord has a #11 in the B note. Again, if writing it out, I'd write Fmaj#11.

Amin has a b13 in the F note, so I'd write Amin7b13.

And Bhalfdim has a b13 in the G note, so I'd write Bhalfdimb13.

I know I may never use these chords, but I'm just wondering if I have the logic right on how to name these ones.

Also, extending the chords this way, am I right in thinking that in Cmajor, I can have an Emin6 chord (E G B C), and an Amin6 chord (A C E F), but my Dmin chord (D F A B) would be a Dmin(maj6)? Or is the other way around (Eminb6, Aminb6, and Dmin6 in C major)?

I'm a little confused about what interval the 6th is from the root on a min6th chord, basically.

Thanks guys, this forum is awesome for helping me grow. Appreciated.

[mr. beaumont]

that's all correct. once you get into extensions, it's best to think of them from the major scale of the root, not the parent scale the chord was harmonized from.

So when thinking about an Em7 type chord, I'm actually looking at the chord from the E major scale, and the formula, of course, is Root, b3, 5, b7. Extensions come from there.

But if you're harmonizing the scale and staying diatonic to the parent scale, like you were, you see how the modes have chordal equivalents--that Esusb9-ish chord will sound lovely with the third mode of C major--E Phygian.

[Scrybe]

Cool, thx Mr B. So is a min6 chord one with a min6 from the root, or one with maj6th from the root? I'm good with C6 being C E G A, but is Cmin6 C Eb G A? Or C Eb G Ab? That's the bit I'm stuck on.

[mr. beaumont]

C, Eb, G, A. Stick with the major scale for all chord spelling and your golden.

So in other words, based on the major scale, a Cm6 is a C triad with a flatted third and an added sixth.

1, b3, 5, 6.