Harmonizing a scale - building chords on a scale

New Member
Joined: 03/17/00
Posts: 23
I know how to harmonize a normal scale to 4-note chords (maj7,7,m7 and °), but I lately wondered how I may build the chords on a minor scale(not really, but the song i played this chord was in the blues shape and the minor pentatonic/blues scale fit it well) if the first chord is an A7#9.
I just built the other chords on the minor scale with a D# (#9 in C major) instead of a D in them, but I wondered if I should take a #9 of A minor although the chord was a major one.
Any help would be apperciated. Tobias
# 1
Jon Broderick
Joined: 10/31/00
Posts: 3,320

Hummm...this is some pretty esoteric stuff here. My first question would be, does it sound good? Cuz if it does, there you go. Go with it. But on further reflection, I think the question is this "isn't a sharp 9 the same as a minor 3rd?
In C, the minor 3rd is Eb.
In C, the 9 is D.
In C, the #9 is D#.
D# = Eb.

On a major chord, that would sound pretty dense and dissonant. Is that what you wanted?

Jon Broderick
Guitar Tricks Instructor

www.GuitarTricks.com - Home of Online Guitar Lessons
# 2
Kevin Taylor
Guitar Tricks Instructor
Joined: 03/05/00
Posts: 4,722
wow...who can think in terms like that?
I feel like I'm back in math class.
# 3
New Member
Joined: 04/07/00
Posts: 14
Hi Tobias!

An A dominant seventh (A7) chord occurs naturally in the key of D major. It could occur accidentally in other keys, though

There's only one naturally occuring Dominant 7th in any givin diatonic Key...

(Though more than one, such as an A7 and a D7, could occur in the same song, but one of them would probably be marked with accidentals, I think you can check out the Jazz standard "Caravan" if you want to see it in action)

Chords are named and formulad by their name-scale, so a chord named A <Anything> or referred to by a formula like 1 3 5 b7 #9 refers to the scale that names the chord, rather than the scale of the key in which it occurs.

An A7 would be spelled AC#EG and an A7#9 would be spelled: AC#EGC(B#)or ACC#EG, with the C(B#) being the Sharped 9th. It would be spelled like that no matter what key it occurs in. Is that the chord that you meant?

The A minor pentatonic scale also shares all 5 of its notes with the D major scale.

*I am still assuming that the key is D Major, because that is the key in which an A7 chord would naturally occur*

So, assuming that the pentatonic you are using is A minor ACDEG, you might interpret a sharped 9th as being the C, which changes the A minor into an A major... Which means that you forgot that you discarded the Scale-Key 9th when you made it a pentatonic scale... hehe!

Or you might interpret the sharped 9th as being the D, which makes perfect sense because not only is the D#/Eb the "Blue-Note" or flatted 5th of the A minor blues scale, it is the 9th (or 2nd) of the C major scale! BUT, a chord is named by its name-scale, not the Key-scale that it occurs in.

Okay, I just tried it out, and it sounds pretty cool in a clean jazz-blues style
This is the inversion that I used:

E |---3---|G
B |---2---|C#
G |---2---|A
D |---2---|E
A |---3---|C
E |-------|X

What did your chord look like?

Anyway, if that's the chord you were using, what key were you playing in? It could still be D major, I'm guessing... the A7#9 sounds good next to a D major, but I don't think that the E minor really fits in (I am looking at this from a 12 bar-blues persective: If A7#9 is the I chord, then E Min would be the V chord...)

Aw, hell! I just re-read your post, and you said right out that you meant #9 as in D#! hehe!


hey... will someone please answer my question on notation?

Sharp, Flat, I'm the one with the axe.

[This message has been edited by Mordant (edited 04-09-2000).]
Sharp, Flat, I'm the one with the axe.
# 4