Piano World Home Page Forums Our Most Popular Forums Pianist Corner - Non Classical Theory Question on The Altered Scale (or Dim. Whole Tone)

I just got a Jazz Lesson recently, and my teacher gave me
a photocopy with the Altered scale around the circle of fifths.

For each key, there is the Altered scale over the Dominant 7th chord, which is C Altered over C7, which everyone knows well.

However, there is also the Altered scale over the minor 6th chord a half-step above the root, or C Altered over C#m6. This sounds good to my ears, as all the chord tones are within the scale, but I have to admit I didn't know about this particular usage of the Altered scale.

Additionally, for each key, there is the Altered scale over the
Augmented 5th (or flatted 6th) Major 7th chord, or C Altered over AbMajor7. This usage doesn't sound quite as nice as the m6 chord.

But still, I'd like to know how people derived the m6th and #5Major7 chords. Did they just discover it by how Jazz composers used the Altered scale?

Any advice on how to use these two chords over the Altered scale is greatly appreciated, thanks!

Hi there,
I have been a long time reader, but never posted before. I just saw your question and thought I might be able to help.

If you start the altered scale on the second scale degree, the b9 of the dominant chord, then you are simply playing a melodic minor scale. That is the reason why it's working over the -6 chord.
You will understand it if you look at the melodic minor scale the same why you would look at the modes ionian, dorian, phrygian...

The same way Lydian functions as a major scale over a maj7 chord, the modes of melodic minor function over their respective chords built on each scale degree.

Check this out:
https://en.wikipedia.org/wiki/Jazz_scale#Modes_of_the_melodic_minor_scale

Of all these modes the most used are:
melodic minor, the first mode
the fourth Lydian Dominant (Lydian with a b7)
the sixth Locrian natural2
the altered scale which is the seventh mode.

Certainly the other modes are used by some people I guess, but I haven't used the others personally and found that these are indeed the most used modes.

Thanks for the explanation! Your time is appreciated.

I'm aware there are modes for any scale, but I forgot
the Altered scale is derived from 7th note of the melodic minor scale, thanks for reminding me.

But the fifth note mode of the MM scale is the Mixolydian b6, which is what my teacher's scale sheet says should be played over a Major 7th chord, which in this case would be C# melodic minor over Ab Major 7th.

This kinda sounds ok, but doesn't seem to fit as well as the other two chords, which is why they are used more often, right?

I think that mode is from the sixth and for a maj7#5 chord.