A7 chord substitution confusion

If its that bit at the start (the intro tune where he walks up the neck while strumming), I often do it, but I never thought about it as "different A7 voicings", I always thought about it as playing a combination of major n minor 6ths (harmonising using the A major scale, I guess) over an A drone. I always heard it as the chords as being different if fully strummed for, say, a bar or two each (tho I'll use them over the A7 section of a 12 bar - I'm less likely to do it with a full band than when playing solo). Yeah, I do that on the E as well, now that I come to think of it. And a few tunes have similar things going on.

Sorry I'm not more help - I'm knackered! Had a completely futile practice sesh today and ended up carrying weights instead. Gonna crash out early methinks.

scrybe, i hear them as different chords too, and i am interested in what you say about harminising using major and minor 6ths, but unfortunatley i dont know what that means :oops: is there anywhere i can find out about that?

Scrybe's right (as usual :D ) - Some of those are just embellishments of the A7 chord. He's adding non-chord tones and using them as passing chords between the A7 shapes. Played over an A string drone (and not staying too long on them) means we don't hear them as different chords, we keep hearing the A7 harmony with some fancy decoration.

Oh yeah....for listening, check out Clapton doing Hideaway - the bit where the band stops and he plays a descending figure on the treble strings is maj/min 6ths. To explain the idea...

Using the A mjor scale, suppose you're playing a melody line which (just for my convenience...) happens to be that scale. So you're playing the notes:

A B Csharp D E Fsharp Gsharp A (note to self, must find "sharp" key on new comp)
You could harmonise this line using any interval structure that you want. We'll take the 6th example here, but it applies across the board. So you'd have two lines played simultaneously, one starting a 6th above the other, like so...

A B Cs D E Fs Gs A
Fs Gs A B Cs D E Fs

A-Fsharp is a major6th interval
B-Gsharp is a maj6th
Csharp to A is a min6th
D-B is a maj6th
E-Csharp is a maj6th
Fsharp-D is a min6th
Gsharp-E is a min6th

Whether the interval is a maj6th or a min6th (minor 6th is aka a b6th) will depend on which scale you use, and which degree of that scale the melody note is on. But you can also harmonise in thirds, fifths, fourths, and so on. If my logic serves me well, 4ths, 5ths, and octaves, being perfect, will always be the same distance apart. But if you harmonise in 2nds, 3rds, 6ths, or 7ths, you'll get a harmony line that's a mix of major and minor intervals from the melody line, and the specific mix you get depends on the scale you've chosen. Try playing a major scale and harmonise each note with the scale note a third above - you'll find that you end up playing the prim and third (1 and 3) of each chord from the scale.

6ths are really big in blues, RnB (like, the old stuff...), and soul. The intro to Soul Man also uses them, and I'm pretty sure Hendrix often played sixths on the fade outs of his solos (and/or any bit of a Hendrix solo where you basically hear him repeat picking two notes over and over rapidly). If I could remember the intro to Green Onions, I'd hedge a bet on that having 6ths in it, too, but don't quote me (I've lost all recollection of how it goes, tbh). I like them, they're a really cool chord-but-not kinda sound to my ears (i.e. more harmonically interesting than just playing octaves....not to mention easier on the hands!).

And I've typed all that assuming you know about minor intervals. I hope it makes sense. If not....

All intervals, starting from a C note:
C-Csharp - min2nd (b2nd)
C-D =maj2nd
C-Dsharp=min3rd (b3rd)
C-E=maj3rd
C-F=perf4th
C-Fsharp=augmented4th (or diminished 5th, depending on the context, but it sounds the same)
C-G=perf5th
C-Gsharp=min6th (or aug5th, again depending on context) (b6th)
C-A=maj6th
C-Asharp=min7th (Bb) (b7th)
C-B=maj7th
C-C=octave

It doesn't matter if the key/tonality is major or minor, anytime you see C note followed by (or at the same time as) an A note, you can say they're a maj6th apart. You're always working from the lower note of the two in comparison. This is why you'll see scales described as being constructed as

1,2,3,4,5,6,7,8
1,2,b3,4,5,6,b7,8
1,b2,b3,4,5,6,b7,8

and so on. The b2 (or min2nd) is the pitch distance being counted from whatever note you call 1. That's true of scales and of any two-note interval you're looking at.

*Notes Fretsource's comment above and grins rather sheepishly. Heh heh, all this jazzing has made me feel like a theory baby all over again! Glad I can pass some of my learning around.

Now that I come to think of it, if you tried harmonising in 5ths using some of the weirder jazz scales, you may end up with some augmented5ths or diminished 5ths in the line. But don't quote me on that, I've yet to try it and am only just learning some of those scales, so I'm really not sure. Suffice it to say that for most purposes this isnt the case.

thanks scrybe - i get what you mean now. im going to try it on some other chords tomorrow.

No worries. I checked out Green Onions in Spotify earlier tho, and it def doesn't have 6ths in the intro. My bad! I should pay that one regularly as its one I always forget if I haven't heard or played it in a while. That, and the entirety of John Scofield's A Go Go album. Love both grooves, just never can remember them once the music stops. :oops:

I do that al the time myself, usually from the 12th fret in the key of G, but I use that style anywhere there's a "A" shape chord.
You could of used those voicings differently also
ascending....A,D,C,D,G,F,G,G,A....etc
A & C shapes

there are some great answers here, and thanks for that, but im still having trouble implementing this in practice (apart from on the A chord as the video shows exactly how to break it down).

can i just ask a few questions?

1) if i wanted to do something similar for an E7, i assume i need to have an open e string hit constantly to give it the feel of an E chord?
2) i assume i will also need the open D string hit constantly to give it the feel of the 7th
3) if its blues is in A, but i am on the E chord, do i harminize on notes in the A major scale, or E major scale?
4) are there any "closed" positions that this could be used with (as that would make it far easier to transfer to different chords.

sorry to ask again about this, but when i try to come up with my own harminizations (is that a word), it all goes pear shaped.
p.s scrybe, i meant to ask you about this on sunday, but hadnt realised how fast the time had gone when i had to leave.

can i just ask a few questions?

There are several hundred smarter people around here, but I'll give this a shot.
1) if i wanted to do something similar for an E7, i assume i need to have an open e string hit constantly to give it the feel of an E chord?

If you are playing all by yourself, it's helpful to anchor the harmony that way. There are other ways to do that; if you've established the E7 to get it strongly in the listeners' ears, you can probably get by without it. If you're working with a bass player, forget it -- that's his job.
2) i assume i will also need the open D string hit constantly to give it the feel of the 7th

I shouldn't think so. Since you're skating around on major and minor sixths, you'll touch on the D natural along the way.
3) if its blues is in A, but i am on the E chord, do i harminize on notes in the A major scale, or E major scale?

You're still thinking in A major, where E is the dominant. E major scale calls for a D#.
4) are there any "closed" positions that this could be used with (as that would make it far easier to transfer to different chords.

I will now step away and let real guitar players/teachers advise you on that. :?

thanks crow for those answers. they were both useful and appreciated :D

yea, I play the A and D strings when doing it on an E7 chord, sometimes also the low E depending on context and/or the high E and B strings, again depending on context.

I also screw around with the C chord, or a Cadd9 chord and move that up to D (try it on Sweet Home Alabama mebbe). And there's a way of harmonizing the D major scale using just the top three string that can be quite good and folky, but I can't remember what I do exactly there just now.

I just watched this video... they aren't substitutions at all.

Look at what he's doing on the fourth string: E-F#-G-A-B-C#-D-E. And on the second string, he's doing C#-D-E-F#-G-A-B-C#.

So all of the fingerings he's using are from an A mixolydian scale, harmonized in sixths. The reason it's the mixolydian scale is the b7 in the scale gives you the b7 in the A7 chord. The reason he's thinking of them as substitutions is that his starting and ending points are the sixth from E-C#, and with the A and G as drones, A7 is what he gets. It's really no different from him playing an E blues scale riff instead of an E chord... the tonality fits what your ear expects from a 12 bar blues.

You could do this in the key of E pretty easily, fingering the harmonized scale on the 5th and 3rd strings. The E mixolydian harmonized scale will work out to frets (5th string shown first, then the 3rd): 2-1, 4-2, 5-4, 7-6, 9-7, 11-9, 12-11, 14-13.

Those are really the only keys you can work with to get this exact effect. But you can use a scale harmonized in sixths in all keys - just don't add drone strings. They're especially good for a country rock type of sound.

thank you noteboat. i had another bask at this last night for E, and came up with the same fingerings you just stated there. you should have seen the relief on my face when i saw you did the same :D

so A and E are the only ones which use open drone strings - that is very useful to know, thanks. in a way i think that makes it a lot simpler for me. thanks. :D