Hey Friend,
Hope you had a good weekend. No, I didn't get an email out yesterday, so your mailbox is fine. I got a bit wrapped up in fine detail work (unfortunately, the mundane kind) that the day got away from me.
Getting back to the key of G major, the next chord up is A minor (Am). We talked about Am as the six chord (VIm) in the key of C major. Here, Am becomes the two chord (IIm), so a little different focus. As a six chord, the focus is on raising up to the octave. There's a feeling of anticipation, that you're getting closer to your destination.
I IIm IIIm IV V VIm VII° G Am Bm C D Em F#°
With G major, the tonic chord is pulling at Am, trying to bring the emotional force back to G. Like gravity, or a parent that's not quite ready to let their child go out and do something on their own. There's loss and anticipation rolled up in the two (IIm) chord.
A minor consists of the A, C and E notes. While each of these notes is part of the G major scale, the chord is actually constructed by taking the A major scale and using the flat third note from that scale. Check it out:
A Major = A B C# D E F# G#
The A major chord is A, C# and E (1 3 5), so when we flatten the third (1 3b 5), we have A, C and E - the A minor chord.
There are nine different positions up the guitar neck for the Am chord. Here are the exercise files.
The A minor chord shows up in six different keys, so let's look first at the major keys:
Key I IIm IIIm IV V VIm VII° G G Am Bm C D Em F#°
C C Dm Em F G Am B° F F Gm Am Bb C Dm E°
And the minor keys:
Key Im II° III IVm Vm VI VII Am Am B° C Dm Em F G Dm Dm E° F Gm Am Bb C Em Em F#° G Am Bm C D
Again, because we first saw A minor in the key of C major and spent almost a week talking about the chord, this is meant more as a review. Here are the exercise files for the A minor chord. If anything is unclear here or in the exercise files, please let me know.
Peace~
Dave | 
