Originally Posted by: kvsealegs

I found that doing the progression correctly didn't sound quite right.

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Exactly what were you playing that didn't sound right?

[quote=kvsealegs]I tried it on several different guitars all tuned correctly and still I came to the same conclusion that it sounded best in the way that I played it and it doesn't fit into any key signature that I know of. It may be closest to the key signature of C, but the B should be diminished.

The sequence went as follows. open Am - barre F - barre G - barre C - barre Bm - open Am.

Is there an explanation why this works. The sequence does seem to work regardless of the rhythm I put to it. Maybe it only sound right to just me...

You are right that those chords do not all belong to one key. That means you've got a modulation.

You could be in A minor (or C major) until you get to the B minor chord. At that point you are modulating to G major.

Or you could be in G major until you arrive at the F major. At that point you are modulating to A minor (or C major).

I would regard the progression as being mostly in A minor because you start and end on that chord. But you really need to specify a melody to be clear about it.

Hope this helps!