Hey guys, I know about finding the notes in a scale and whether chords are in a key and stuff, but say I was doing a I IV V progression in key of G, so that would be G C Dm (correct me if I'm wrong) and wanted a mellow sound and wanted to change everything to minor, could I just make it Gm Cm Dm or would that be wrong? Also If I had something like G C F chords, would It be ok to make it like G7 C7 F7 etc. for other types of chords? Any help is appreciated, thanks in advance.
A "I IV V" in G is G-C-D, not Dm.

Yes, you can make them all minor, giving you a minor i-iv-v (yes, case matters).

You can play around with dominant chords quite a bit because of their inherent tension. Just mess around and think about what sounds good.
Looking for my India/Django.
It might not (probably won't) be in key, but anythign is acceptable if it sounds good.

Gm Cm Dm is i iv v in G minor, but G7 C7 F7 does not fit in any key.
G C Dm is in the key of C somehow.
C7 F7 G7 are the chords of a blues in C.

For the rest, redwing&bgc are correct.
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