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:
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).]