Some b5/#11 Chord/Scale Questions

[Mike A]

7b9#11 and 7b5b9 are (I think) enharmonic chords, if you're focusing just on the explicit chord tones, but should these two different symbols be understood to imply two different scales? One alt, one HW dim? If so, which is which? Both of those scales include the b9 and the note that is the #11/b5.

And how about the impact of adding 13 to each of them: 13b9#11 and 13b5b9? It definitely rules out the alt scale, which has no natural 13.

Thoughts?

Thanks!

[gennation]

Basically if you're flatting the 5, the perfect 5th isn't "assumed" to be in the chord anymore. But, if you sharp the 11 the perfect 5th is still "assumed" to be in the chord.

So scale wise, the b5 chord would have the P5 replaced with the b5, and the #11 would have a half-step Interval between the #11 and P5.

IOW, use a #11 if the P5 still exists, or use b5 if you've replaced the P5 in the chord/scale with a b5.

That's it in a nutshell.

[Mike A]

Thanks.

If you assume a perfect fifth in the scale corresponding to 7b9#11, presumably that means that the scale is HW diminished, because it includes a P5 and a #11 (and a b9). Correct? This scale will also work if you add the 13 to the chord symbol, because the HW dim scale includes the natural 13 (6).

Now, if I apply your same approach to 7b9b5, should I assume that the scale includes a natural 11 (and a b9 but no P5)? If so, what is the resulting scale? The alt scale and the HW dim scale both have a b5, but neither one has a natural 11. (As far as the 13 goes, the alt scale doesn't have, but the HW dim does.)

[Phil Kelly]

Thanks.

If so, what is the resulting scale? The alt scale and the HW dim scale both have a b5, but neither one has a natural 11. (As far as the 13 goes, the alt scale doesn't have, but the HW dim does.)

dont forget : the DESCENDING version of the HW scale is the WH ..both of which contain the 13th.

[Mike A]

But what scale corresponds to 7b5b9 and to 13b5b9?

[JoeNovice]

7b5b9 = Altered Dominate (play 7th mode of real melodic minor. aka Super Locrian, Diminished whole-tone, RMM starting on b9)

13b5b9 is not a standard harmony and likely wouldn't be named as such. Most likely it would be best called a polychord.

G, Ab, B, Db, E, F

These notes could be grouped into a Db|Emin poly chord.

If you removed the b5 or 13 the scale could fit into common scales. Aside from that something synthetic would need to be created. You could also remove the root and create an altered Tritone sub. (G13b5b9 would become Db7#9)

G,Ab,B,C,Db,E,F is not a scale that I know.

[guitarjazz]

13b5b9 is simply generated by the dim.scale, of which you can move to voicing up in minor thirds. A nice tune that uses that chord is Pools by Steps Ahead. There is a chart for it in one of the Chuck Sher fake books.
Unless I'm harmonizing a melody anything is fair game on any seventh chord.
The G,Ab,B,C,Db,E,F is a mode of the C 'Persian' scale. Great sounding scale and I once played a Persian wedding where we played several songs using it and the people sang along like we sing Happy Birthday.

[JoeNovice]

13b5b9 is simply generated by the dim.scale, of which you can move to voicing up in minor thirds. A nice tune that uses that chord is Pools by Steps Ahead. There is a chart for it in one of the Chuck Sher fake books.
Unless I'm harmonizing a melody anything is fair game on any seventh chord.
The G,Ab,B,C,Db,E,F is a mode of the C 'Persian' scale. Great sounding scale and I once played a Persian wedding where we played several songs using it and the people sang along like we sing Happy Birthday.


Nice... C Persian Scale. I guess you can always count on a scale name for any collection of notes.

Just to go overboard on this..... if you use the dim.scale to create that chord, technically, it would be called 13b9#11 since that scale has the natural 5th.

[guitarjazz]

You can drive yourself nuts trying to correctly spell chords. Also you may ere by believing too literally in the chord symbol. For instance, G7b9#11 might be written Db/G7. Now what is it and how do you spell it? Does it matter how you spell it or is how it sounds more critical?

[JoeNovice]

How it sounds is the ONLY thing that matters!

But you can't discuss how it sounds. You can only discuss the theory of the sound. If you want to talk about chord/scale relationships you must be accurate. Otherwise, you aren't communicating correct meaning.

You can drive yourself nuts trying to correctly spell chords.
I totally disagree with that statement but totally agree with this one;
Also you may ere by believing too literally in the chord symbol.

[guitarjazz]

In the Joe Pass Chord Book he doesn’t even name the chords, other than their genre. In the introduction to the book he articulates his reasons for doing this.