If anyone's available, I have a theory question? Baffled by chord progression.?

Question

In my attempt to learn about chord progressions I have come to this sequence which baffles me.

A- D- A- D- E- A- D- E- F#m- G

I IV I IV V I IV V iv ???

I'm just confused about the G chord. How does what I figured "should" be a G#m dim chord turn into a G major chord?

Thanks if anyone can help. :-/

That's not the full progression by the way, the end of the song continues onto l: A-D-A-D :l in case you were wondering or also baffled in some way.

Answer 1

I see the G major chord coming in as a fine transition back to the key of A.

After the G chord it seems an E chord with its dominant seventh, or the G#dim7, should interface before the A chord again. Yet, running through the progression the melody cries for the new key of D major.

Answer 2

Hmm.... well, first off, let's count sharps. A major has C#, I see an F# in the F#m and D major... The order of sharps is F C G D etc...

So here's the thing... E major has a G#, which implies three sharps in the key signature, which implies A major. But the F#m to G bit breaks with that, turning the progression briefly into D major, if you will (key signature of two sharps instead of three).

So I would call it modulation, I suppose, vs a parallel tonality chord, because if the progression goes on like that, you'll notice that the G isn't sharped (in the chords at least) through the rest of the progression. In fact, the sequence ends on D, which I think supports this analysis further.

so

A( I - IV - I - IV - V - I - IV - V - bvi ) - D( IV - V - I - V - I )

I'm sure there's a better way to write out a modulation than this, but that's what you get when you never study formal music theory in school.

I like the way the chords ascend... D E f# G A. Seems like it would help support the progression through the modulation.

Saul