So i'm listening to something by bach in G. I've been studying as much music theory as i can, writing out major scales and trying to work out how chord progressions work. I also have been playing around with relative minor chords which is a nice thing to have in your arsenal thanks to that wonderful marty friedman Melodic Control video.

Anyways going back to Bach in G minor, i understand that a G major chord contains the notes G,B, and D. So a G minor chord structure would be G,A#, and D.

Does that mean that if it's in the key of G minor, it will have a chord progression of G, A#, and D?

Either that or does it follow from the G Aeolian scale?

I'm sure i can keep asking questions about this or that, but it's nice to get feedback from people that understand it better than I.

^ it would actually be spelled

G - Bb - D

for G minor. those are the notes used in the chord G minor

there are virtually limitless possibilities for chord progression in G minor

don't concern your self with Aeolian, thats a mode which is derived from a scale and something you don't need to concern yourself with right now.
First of all, a G minor chord is G, Bb(not A#), and D because it's built with thirds. And to answer your question, a song that is in the key of G minor can have an infinite amount of different chord progressions, it will just mostly like start with a I chord (which would be the G minor chord), then it can go anywhere from there. And the notes don't have to follow the G Aeolian scale, it can be G harmonic minor or melodic minor which will change some of the chords as well. I hope this paragraph isn't too confusing.
Quote by Kant
Does that mean that if it's in the key of G minor, it will have a chord progression of G, A#, and D?

First off, that should be G, Bb, D because the key signature for G minor is 2 flats. Second, the progression isn't set in stone. As long as the chord fits in the key and flows smoothly to other chords, it works. Usually the tonic, sub-dominant and dominant chords appear most often. So in G minor that would be Gm, Cm, D(7)
Ah okay, i was thinking that the progressions had a lot of possibilities. I've seen the stuff like I ii III iv etc.

I'll look up more stuff on chord progressions and study it more :P

Thanks for the help!