Why b9sus4?

takauya · #1 03-22-2010, 03:24 AM

Could anyone tell me why b9sus4 isn't min7?
It's from the second mode of melodic-minor scale, so isn't it Dmin7 if it's based on C melodic-minor scale?

I mean D7susb9!

itsall4you · #2 03-22-2010, 04:09 AM

If you take the upper structure of the Second degree of the melodic minor scale.

You get the b9 11 and 13.

I think it's simply utilizing the upper structure of the chord.

The necessary notes for D7sus(b9) is D C Eb G

The Eb and the G are from the upper structure.

I don't know what you are doing with the chord but D7sus(b9) IS Dm7 in this context.

It's the same way that you would add 13ths and 9ths to a D7 chord.

I don't think I'm explaining in clear enough but hope you got what I meant

takauya · #3 03-22-2010, 04:19 AM

Thanks, itsall4you

I looked at this thread http://www.jazzguitar.be/forum/theor....html#post7411
I think it's also written on the Mark Levin's Jazz theory book.

I wonder why it's D7susb9, not Dmin7.
D Dorian b2 D Eb F G A B C
This can't be D7, right? no F# in them.
and why sus7, not min7?

What am I missing here?

itsall4you · #4 03-22-2010, 05:10 AM

sus7 because there is an 11th instead of the 3rd.

Yes you're right it is in fact NOT a dominant chord.

It's really should be written as Dm11b9(omit 3rd) because it doesn't have a dominant 7th character.

But it IS a minor chord but with upper extensions..

itsall4you · #5 03-22-2010, 05:15 AM

If you're referring to this

1 CmMaj7

2 D7susb9

3 EbMaj7#5

4 F7#11

5 G7b13

6 Am7b5(nat9)

7 B7alt(b9,#9,b5,#5)

What m78w has done is he's written the common chords we associate with melodic minor but added upper extensions and important colour notes in each chord.

Without the upper extensions, (going up to the 7ths)

The chords would be in Cminor

1. C minor major 7
2. D minor 7
3. Eb major 7 #5
4. F7
5. G7
6. A half diminished or A minor 7 b5 (same things)
6. B half diminished or B minor 7 b5 (again, same things)

takauya · #6 03-22-2010, 06:45 AM

I see. That's clear.

I'm not good at chord names.
I see a lot of 7sus chords in the comtemporary songs.
I'm always annoyed by it.

and what is "nat9"?
6 Am7b5(nat9)

itsall4you · #7 03-22-2010, 06:54 AM

The nat9 refers to the natural 9.

Normally, when you see a m7b5 chord you associate it with a scale called 'Locrian' it's the 7th mode of major.

The Locrian scale has a flattened(b) 9 in the scale which is the avoid note.

So what natural 9 means is that instead of the b9 it will use a natural 9. Which is the 6th mode of melodic minor. And this scale is often called Locrian natural 9 OR Locrian #2 (this refers to the original b9 of the Locrian scale. the b9 is sharpened to a natural 9)

If you kept going up this arpeggio using the Locrian Natural 2 scale. It would make 1 b3 b5 b7 nat9 nat11 b13.

As to 7sus chords, they are different from 7susb9 chords. 7sus chords are just (mostly) a V chord in a major key with a suspension. You can also think of it as a IV/V chord.

JohnW400 · #8 03-22-2010, 07:15 AM

Fast an easy way to find the 7 sus b9 is to play the minor7th b5 up a 5th from the root

D7susb9 = Ami7b5/D. The Ami7b5 is the 5,7,sus and b9

takauya · #9 03-22-2010, 07:18 AM

Thank you. I understand about the 7susb9 chords and the Locrian natural 2 scale.

Could you give some more explanation about the 7sus chord?
Does "sus" mean sus4?
What is the IV/V chord?

JohnW400 · #10 03-22-2010, 08:10 AM

Quote:

Originally Posted by takauya

Thank you. I understand about the 7susb9 chords and the Locrian natural 2 scale.

Could you give some more explanation about the 7sus chord?
Does "sus" mean sus4?
What is the IV/V chord?

Sus refers to either the 2nd or 4th. In this case it's the 4th.

Regarding the IV/V I'm not sure what you mean. It looks like you're refering to the IV and V chord of a progression ( Fma7, G7 in C) or it could be a polychord IV over V .

bako · #11 03-22-2010, 08:13 AM

Every mode has many harmonic possibilities influenced by the contributions of each tone. Replacing the 3rd with 4th is always an option either as a resolving suspension or a structure unto itself.

Re: D7susb9

The literal notes do not include a major 3rd but can still function against a D7 chord.

D-1
Eb-b9
F-#9
G-4
A-5
B-13
C-b7

The most common instance of a scale lacking a major 3rd being played against a dominant chord is the minor pentatonic.
DFGAC against D7

Sometimes a mode can be used because of what is there even though it's missing a basic chord tone.
In real terms a chord is formed by the sum total of all the notes played by the band and not just the melody line.

timscarey · #12 03-22-2010, 10:29 PM

Quote:

Originally Posted by takauya

Thank you. I understand about the 7susb9 chords and the Locrian natural 2 scale.

Could you give some more explanation about the 7sus chord?
Does "sus" mean sus4?
What is the IV/V chord?

7sus4

7 means that it is a dominant 7th type chord

sus or sus4 means "suspended fourth" it's putting the 4 in the chord instead of the 3rd.

These chords are only heard as having a quality (either minor or dominant) in context. on their own, they rely on nothing but the notes being sounded in the moment and the feel of the music. It is quite common to use a 7sus4(b9) sound on vamps using sus4 chords.

It really just depends on what the other people are playing at the moment, sus chords have as many possibilities as dominant chords