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View Full Version : Harmonizing a scale - building chords on a scale

Tobias
03-31-2000, 08:04 AM
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

Jon Broderick
03-31-2000, 02:04 PM
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?

Kevin Taylor
03-31-2000, 07:41 PM
wow...who can think in terms like that?
I feel like I'm back in math class.

Mordant
04-08-2000, 09:01 PM
Hi Tobias!

An A dominant seventh (A7) chord occurs naturally in the key of D major. It could occur accidentally in other keys, though http://www.guitarforums.com/gtubb/tongue.gif

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 &lt;Anything&gt; 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:

(Tab)
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!

Doh!