Extended chords, up to 13ths, over diatonic scales?

[Bob]

If anyone wants to chime in....

I figured out what I was looking for seventh chords over a major scale or minor scale (which turned out to be melodic minor).

I was thinking about ninths that way, but then figured why not up to 13ths and be done with it.  

Would it be....?
I    1 3 5 7 9 natural11 13    
ii    2 4 6 1 3 5 7... 1 m3 5 m7 9 11 13
iii   3 5 7 2 4 6 1 ... 1 3 5 7... m9??? 11 13
IV  4 6 1 3 5 7
V   5 7 2 4 6 1 3
vi   6 1 3 5 7 2 4
viio 7 2 4 6 1 3 5

I'm not quite sure when it comes to 11ths, with the m9 clash.   Maybe it should be a raised 11th sometimes?  


Minor was starting to really confuse me, with the diminished chords.

And then again, once notes are that high, it might not matter what they are.  If the base is M, m, V, or dim, that's what controls the function.  The rest is just color.

[Bob]

A thirteenth chord over I is a good one. 

Is it a natural or raised 11th?

1 3 5 7 9 11 13

Because the 11 (4) will create a m9 and clash with the 3.  So... raise the 11th.  Problem solved.  Right?  So I13 should really be...  I#11 13, right?

I end up with...
I #11 13
ii 13
ii i#9 13
IV 13
V 13
vi #13
vii/o #9

[nystul]

I don't think you can come up with some definitive right answer for these.  It depends on the context.  A dominant 7th chord could potentially use b9, 9, or #9 as long as it fits the piece.

Your 11th on a I chord, tricky stuff.  If you take a C major chord and throw an F on top, you actually have a sort of suspended chord instead.  Sounds like it needs resolution.  On the other hand, in a modern style you can throw in the F# and still have the original function of the chord.  But what if the melody goes like GFE?  Then I don't think you want to have an F# (or Gb) in the harmony!  Maybe your "singer" will give you some dirty looks!

[Bob]

Or the options available.  Typical forms of chords when they get up there.  I just want to know what the typical options are.  I should pull out my Jazz Piano Book.  I think that's where I read about the 3rd/11th m9th clash.

It's more of a theory exercise kind of thing. 

[Bob]

This is what I'm coming up with.

For a major scale, with 13ths over it.  I need to let this sink in more.

Basically it's just raising the upper/extended note a half-step when it clashes with the 3-4, 7-8 steps... So it's just watching for the 3rd step and 7th step of the scale in chords.

In C...
CM7/D7
d7/e7
e7/f#/o7
FM7/GM7   (This is a weird one.  The only chord in this group where the 15th isn't the root.  It's that 7 degree/7-8 half-step thing again, so the 15th is raised.)
G7/A7
a7/b7
b/o7 / c#/o7

It's kind of strange for the chords built on 2, 4, 5, 6, and 7.  If it's divided up into two seventh chords for ease of thinking it's two of the same quality...
step 2 = m7 + m7 [Each upper seventh chord listed here is up a WT from root]
step 4 = M7 + M7
step 5 = V7 + V7
step 6 = m7 + m7
step 7 = /o7 + /o7

The others...
step 1 = M7 + V7  
step 3 = m7 + /o7    
....
And it's always the 4th degree or 1st degree that's raised, raised half-step from the 3rd or 7th step to get rid of the m9.

I #11 13
ii 13
iii #9 13
IV #15 I guess the way I'm playing the chord, two sevenths in each hand.
V7 #11 13
vi #9 13
vii/o7 #9 13
... if I'm writing those correctly.  That would have everything under the 13th present.

[Bob]

Duh on me....

It's much simpler. 

I've been doing 15ths, not 13ths.  And that actually makes things simpler to understand.

It's just two sevenths, stacked on top of each other, a whole tone apart (so the right hand seventh's "root" is a whole tone above the LH's root.)

And what I listed above was a little off. 

All what you do is repeat the quality of the LH's seventh chord, a WT up in the RH.

M7
m7
m7
M7
V7
vi7
vii/o7

Just like seventh chords. 

I'll have to go back and double check the quality.

That prevents m9 clashes.  There are still some chords that have some M7 dissonance though.  I still need to look through my Jazz Piano Book/Levine. 

[Bob]

Grr... This still isn't right.  Matching seventh chords works fine to prevent m9s.  But M7s (in some spelling) are still there and there are a few chords where the m9 is taken away from the 7th and 15th clashing, but raising the 15th a half-step makes a clash between the root and 15th. 

The Levine Jazz Piano Book looks a lot simpler than what I remember in the past.  And it's not the book I was looking for, I don't think.  I'm thinking it's Jazz Theory by Mark Boling that I was thinking of. 

[Bob]

Ah ha... I found it.  Pg. 31 Boling....

If I'm reading this chart right.  It's ok to add the following to the base seventh chord....

M7, 9, #11, 13
m7, 9, 11, 13
/o7, 9, 11, b13
V7, 9, #11, 13
o7, o7 chord a major seventh above the original (I guess original means root... )

[Bob]

Hmm... I studied the pages of the Boling book. 

If I avoid m9 clashes, I ended up with the same results he did. 

Except I ended up playing 15ths.... And that causes a problem with M7s... M7+M7.  There's either a clash between the root or M7 and the 15th if it's M7+M7 or M7+V7.  And the only way to avoid that is either double the root in the RH, M7+M, or play an M6 instead, M7+M6.  Or let it clash, probably with M7+M7.  The rest ends up like I was thinking.  Actually all of it does.  He just didn't explain 15ths there. 

*Bob is wondering about going higher now... Except he's out of hands.*

[Bob]

I've notice when chords start getting taller, balance becomes emphasized.  Not to mention straining tonality a little more.  I forget which key I'm in sometimes while playing chords over scales.... in part because my ear isn't hearing the tonality anymore I think.  Tall chords can start sounding like a different chord or key if the upper notes are stronger and the actual root is played weak.

I was thinking about jazz.  I'm not a jazzer.  From what I understand though chords and scales are the same thing, interchangeable.  Take a M7, stack a Major triad on top of that, built on the M9 above the root... If you fold that down, you end up with a lydian scale.... I think a lydian scale is equal to a M7 or variation on a M7 chord.  (I think.  I would need to check, but I think that's the idea....)  But... That's folding an extended chord down, when it's a 13th at most.  What if it was a 15th chord or higher?  I suppose eventually you just end up with a chromatic scale, or maybe some microtonal even.  Or that it doesn't matter when chords get that tall.