So the chord sequence for The Sound of Silence in Am (the key I play in because I lost my capo) is roughly
Am G Am C F C F C F C Am C G Am G etc.
My question is why the G before Am, "within the sound," which has a lot of suspense and does not sound bright at all, sounds very different from the G after the Am, which is bright and cheery. It's G Am G, but the two G's sound very different. I took music theory a decade and a half ago and I've long since forgotten pretty much all of it, but I got the sense that the "chord of suspense" should be E or E7, which is nowhere in this piece.