Where Do Maj7 / Min7b5 / Dim7 Chord Tensions Come From?

I hope the teacher can help me to tell me which scales these chords tension come from. For example ,I know that dominant chords tensions come from Alt scale.

Sorry, I want to ask alt tensions. not natural tensions.
For example, CMajor7#4 or Adim b13 chord . This kind of tension come from which scale?

Hi FooChi :wave:

Great question here!

Firstly let’s talk about Major Chords:

For major chords, here are 2 common options to derive harmonies and melodies.

  • Ionian Mode - simply the major scale
  • Lydian Mode - the major scale with a #4 / #11

For every major chord, you can include the #11 colour/tension in your lines, and/or your chord voicings. There are more colours/tensions that you can use over major chords such as the #5, but right now just focus on exploring the #11 and introducing it into your melodies and chord voicings.

For -7b5 Chords (aka. Half Diminished):

First we have the Locrian mode which is the 7th mode of the major scale.

The Locrian Mode

So if you wanted to play a scale over B-7b5, you could either play the B Major Scale with R, b2, b3, 4, b5. b6, & b7, or alteratively, just play the C Major scale from B to B. This is 2 ways of getting the same result, but different musicians do it in different ways.

You can find more information on the major modes here:

The Locrian Mode Natural 2/9

Often jazz musicians will play a natural 2/9 over -7b5 chords. The b2/b9 from the Locrian mode sounds somewhat dissonant, and the natural 2 gives a more ‘exotic’ sound. The Locrian natural 2 scale is a mode from the melodic minor scale.

You can find more information on the melodic minor modes here:

Finally, For Dominant Chords:

There are many more options here.

The b13 / #5 that you mention is commonly associated with the ‘altered mode’, again check out the lesson on the melodic minor modes above. You can also find a more detailed study on the altered mode here:

I’ve been having a very similar discussion with @natasha0412 over in the following thread about the diminished scale.

Check out this post where we compare the differences between the diminished scale, and the altered mode:

I hope this helps FooChi… and if you have any further questions just let me know :slight_smile:

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Thanks very,teacher.
I think I should study your course more carefully.
Thank you very much for your explanation.
You are the best teacher I have ever seen.

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My pleasure FooChi.

Altered tones and ‘colours’ are a wonderful area to study… there’s lots of fantastic sounds for you to explore so have fun with that stuff!

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