Advanced Substitution Harmony question

[idssdi]

Thank to the way John Mayer plays bar chords in the A shape, he plays them with the third in the base, I figured out that C can function as an Am7 and that's what makes a chord progression like D-C-Bm-C work because the when the C functions as an Am7 harmonically it gives a perfect cadence(V-I) this is also why all along the watchtower and the ending of stairway to heaven work, if you strictly take the chords in those chord progressions there is no resolving cadence but if you consider some substitutions there is.

Now I started thinking for a bit and thought that the notes of C can also make up a Em#5, I know augmented stuff only really works for major chords but hypothetically is it possible to resolve to Am by playing a C?

 

[Andrew Milner]

Hm, it takes a bit of mind-bending, but it should be something like this.

We know that an Am chord is comprised of the A-C-E notes. If we were to play the first inversion of this chord, it would be C-E-A.

On a guitar, using the A form of the chord would give the following tab:

E|-----|
B|--1--|
G|--2--|
D|--2--|
E|--3--|
E|-----|​

Let's consider the Am7 chord now. It consists of the A-C-E-G notes. As you can see, the last 3 notes of this chord are basically the notes of a C chord.

Now if we are to attempt to add a G note on the chord above, we'd run out of fingers if we wanted to play it on the E string, 3rd fret. But no one states that we cannot add the G note in a different manner:

E|-----|
B|--1--|
G|--0--|
D|--2--|
E|--3--|
E|-----|
​

So yeah, technically you can...but it does require a bit of twisting and turning.

 

[Chris Johnston]

Thank to the way John Mayer plays bar chords in the A shape, he plays them with the third in the base, I figured out that C can function as an Am7 and that's what makes a chord progression like D-C-Bm-C work because the when the C functions as an Am7 harmonically it gives a perfect cadence(V-I) this is also why all along the watchtower and the ending of stairway to heaven work, if you strictly take the chords in those chord progressions there is no resolving cadence but if you consider some substitutions there is.

Now I started thinking for a bit and thought that the notes of C can also make up a Em#5, I know augmented stuff only really works for major chords but hypothetically is it possible to resolve to Am by playing a C?

Interesting stuff! - Going to take a stab at a concept here:

You mentioned an Em#5 : A way that you could also think about that chord is as an Em b6/Em b13 - As the 'C' note, within the context of E minor gives off an Aeolian sound (b6).

If you're thinking of the Am7 as a ii chord (Dorian sound) then the Emin b6 would logically resolve to that Am7 (An Aeolian sound resolving to a Dorian sound etc) - As they are both relative chords to the key of G Major!

It basically all comes down to voice leading and what sounds good to your ear - You can definitely resolve to an Am7 by playing a C major chord, as they are relative to the same key of G, it just depends on the weight you give to the C chord compared to the A min7.

A fun way would be: C major / Emb6 / Am7 - As in the bass, you get the movement of the notes: C E A, and you have the common tones of C & G on the top of the chord.

Hopefully that made sense and was helpful in some way!