#1
Just a chord question, when is it suitable to use a 9th/11th/13th chord in composition?

I know how they are constructed. Are they just used to replace a 7th chord?

For example, in the following chord progression:


Gmaj7 G6 Amin7 Amin6


could you change the major 7 to a major 9, 11 or 13, or the minor 7 to a minor 9, 11 or 13 and still be technically correct?

What about 6th chords, is there any rules regarding the placement when composing?
#2
Any extension will function the same as it's non-extended equivalent. A Gmaj9 will function like the Gmaj7. This is the same for any alterations, such as #11 or b13. Likewise, a Gadd9 will act like a G. 6's are no different.

HOWEVER, always keep in mind your voice-leading. Using extensions can create a thicker texture which richer voice-leading movements. Your extensions and their context in a chord progression will help you determine where they want to go.

The G6 to Am7 is a good move on your part:

G - G
E - E
D - C
B - A

Notice how the E and G remain constant through both chords, while the others move stepwise.
Nothing that is worthwhile in life will ever come easy.
Last edited by soviet_ska at Jun 22, 2011,
#3
Quote by soviet_ska
Any extension will function the same as it's non-extended equivalent. A Gmaj9 will function like the Gmaj7. This is the same for any alterations, such as #11 or b13. Likewise, a Gadd9 will act like a G. 6's are no different.


this. nothing else to it. if you want to use an Ab7, but you want the sound of a 9th/11th/13th, you use it.
Anfangen ist leicht, Beharren eine Kunst.
#5
Right the only thing I would add is that they add additional harmony notes, and so you have to be careful to respect the melody line comparing it with the upper voicings of your chords, so as not to create a clash in melody and harmony. For example a Minor 6th is usually advisable when the upper voice is in the melody line at that point as well.

Best,

Sean
#6
Quote by soviet_ska
Any extension will function the same as it's non-extended equivalent. A Gmaj9 will function like the Gmaj7. This is the same for any alterations, such as #11 or b13. Likewise, a Gadd9 will act like a G. 6's are no different.

...



Be careful.

Alterations are a different family -- especially over major chords -- altered tones include sharp and flat 5, sharp and flat 9, so you can end up with something that sounds more diminished or augmented. In fact Joe Pass speaks of augmented chords as part of the altered family for jazz comping.
#7
Quote by Zen Skin
Be careful.

Alterations are a different family -- especially over major chords -- altered tones include sharp and flat 5, sharp and flat 9, so you can end up with something that sounds more diminished or augmented. In fact Joe Pass speaks of augmented chords as part of the altered family for jazz comping.


I really consider something with a #5 or b5 to be a chord based off an augmented/diminished triad, respectively. Even though I will often write Dm7b5, I always think of it as a half-diminished 7th, rather than a minor 7th alteration.
Nothing that is worthwhile in life will ever come easy.
#8
Quote by soviet_ska
I really consider something with a #5 or b5 to be a chord based off an augmented/diminished triad, respectively. Even though I will often write Dm7b5, I always think of it as a half-diminished 7th, rather than a minor 7th alteration.


people think of m7b5 as being an alteration? i find that ridiculous. why even have a diminished chord in that case?
Anfangen ist leicht, Beharren eine Kunst.