### A°7 function

#150560  by BOUKINATOR

Hey theory people. Curious how you think the A°7 chord functions (with roman numerals) resolving to the I.

i.e.
#ii°7? #iv°7?

I have a hard time labeling that D# a passing tone with the chord happening on strong beat.

On a side note, a GREAT song to practice playing solos over chords

### Re: A°7 function

#150561  by Lephty

That is a strange one for sure, and I have always wondered about it. I actually think of it as D#dim (which is enharmonic with, aka the same as, an A dim, so the #iv dim in this case). The more typical use of that chord would be D > D#dim > E, in which case it would be called the viidim/V (vii dim of the V chord)--and that may indeed be what it is here, except that they just skip the V chord (E) and go straight back to the I (A). It sounds to me like it works in this case because the D# resolves up to the E (the 5th of the A chord) and the C resolves up to the C# (the 3rd of the A chord). So it's not a standard function for a diminished chord, but it does work.

Now that I think about it, that same kind of thing happens in a jazz blues progression--check out this page, scroll down to the "Count Basie Blues": http://www.jazzguitar.be/jazz_blues_cho ... sions.html. Could be where Garcia got the idea!

One thing for sure, it sounds good...and that's what really matters I guess.

### Re: A°7 function

#173656  by flat5

This is one question that I have been studying. I'll look at it closer, but at first look it doesn't make much sense theoretically. I actually have come to wonder if the transcription has been wrong all these years. I know that transcription has been around for a while. I actually play an Ab dim resolving straight into the Amaj. It comes and goes quickly so it is a bit difficult to hear, but I hear that chord as an Abdim. Play it with the root on the G string first fret and it moves easily into the Amaj. Try it out some of you pickers and let me know what you think.

### Re: A°7 function

#173660  by strumminsix

flat5 wrote: Wed Sep 14, 2022 4:37 pm This is one question that I have been studying. I'll look at it closer, but at first look it doesn't make much sense theoretically. I actually have come to wonder if the transcription has been wrong all these years. I know that transcription has been around for a while. I actually play an Ab dim resolving straight into the Amaj. It comes and goes quickly so it is a bit difficult to hear, but I hear that chord as an Abdim. Play it with the root on the G string first fret and it moves easily into the Amaj. Try it out some of you pickers and let me know what you think.
An Abo7 might sound right solo but it's a half step from the chord the GD are playing.

Think of the changes: D7 to D#o7 to A

That A had an E note as its dominant in the triad. So there's a inquire chromatic walkup from D to E.

### Re: A°7 function

#173661  by flat5

Correction on that Ab dim from Flat5.......I am playing the root on the first fret D string, which appears immediately as a Eb min7b5. I'll write it out and look closer. Now, I am fairly sharp on theory basics up till 4 part writing. However, what I think is going on ( presuming the chord IS a Eb min7b5 ) is a simple tritone substitution for the A maj. It just keeps the ball in the air longer and fills out the resolution. That would make sense theoretically ( i think ) Again, I'll write it out, but the Eb min7b5 works very well. However, maybe the band wanted the dissonance of the Adim7. Anyway, try an Ebmin7b5 in the Adim position and let your ears be the judge. What do YOUR ears hear ?

### Re: A°7 function

#173663  by strumminsix

The movement I'm talking about a single note half step D to D# with the rest of the stacked chord staying planted.

From D7 -- D, F#, A, C
To D#o7 -- D#, F#, A, C

The D#m7b5 sounds ok cuz it matches 3 of the 4 notes: D#, F#, A and C#.

But if you play to Jerry's studio, you'll hear that C# is out of place and that C, which carries over from the D7, is where it's at

### Re: A°7 function

#173665  by flat5

That is essentially what I am playing as well, but I am moving the C in the Ebdim ( D#dim enharmonic ) to a C# along with the the D# moving to an E in the Amaj. About the same thing you are doing, but I am moving the C to a C# in the A maj. as well.

### Re: A°7 function

#173668  by strumminsix

Right, which is why it sounds good. But what do you hear on the recordings? Do you hear that C#??

### Re: A°7 function

#173671  by flat5

The chord goes by quickly and to be honest I haven't really sweated over whether it is spot on perfect. That D#dim just works so well in that song. I don't have perfect pitch and can't necessarily tell you if I can hear the exact C# note, but I hear the dissonance when you play the Adim that is written in the transcription.

### Re: A°7 function

#173672  by flat5

Oh....and remember the Amaj has a C# as the third so it fits well when you resolve to the Amaj. Indeed I don't think it would work without the C# in the Amaj.

### Re: A°7 function

#173701  by wabisabied

I’m no scholar, but I’ll play, anyway.

I think D# makes perfect sense as a passing chromatic walk-up tone between the root of the D7 and the 5th of the A (4 > #4 > 5). Like a lead tone to the dominant chord but landing on the tonic. Then to repeat the theme, there’s a similar chromatic move of the 1 > #1 > 2 within the A > F# > B that follows in the first half of the verse.

One might consider the C natural borrowed from the parallel minor. And if we’re borrowing the C natural from the parallel minor, then the D# (Eb) could be considered the blue note from that parallel minor key. So those notes do make some sense together (b3 and b5), along with the A and F# (1 and 6). So maybe D#/Eb is more than just a passing tone.

So A° functions as i6, as in IV7 > i6 > I, maybe? It’s not diatonic, but who cares?

### Re: A°7 function

#173704  by flat5

Absolutely mu friend. We seem to be hearing about the same thing and playing almost, if not the same thing. Yes, a passing chord would make very good sense theoretically. Remember to take a look at in terms of a tritone substitution as well. I think that may also explain the chord function. Good call.

### Re: A°7 function

#173705  by strumminsix

BOUKINATOR wrote: Wed Jan 13, 2016 9:25 pm Hey theory people. Curious how you think the A°7 chord functions (with roman numerals) resolving to the I.

i.e.
#ii°7? #iv°7?

I have a hard time labeling that D# a passing tone with the chord happening on strong beat.

On a side note, a GREAT song to practice playing solos over chords
Replying to Jim. RIP buddy and wish we could talk again :(

Years ago someone much smarter than I taught me how deal actual uses secondary dominants to shift keys throughout the song.

So while the tonal center is A, mixo scale for much of it. It has lots of rule breakers: C#7, , D#o7 (which is the same as Ao7), and G

I've charted out tons of tunes using Nashville style or Roman numeral style... But this song just isn't one this works well for...