#1
heh i was wondering if i am playing a A minor chord and an F maj 7 what key am i in or is it technically many i can pick from but more sence from one of those 2 root notes?

cause in a minor scale there is an f and in f maj scale there is an a or am i not understanding something here??


edit: or does it not matter?
song stuck in my head today


#2
If you're just playing those chords again and again, the key would be whichever note your melody leans towards. If you progress onto more chords, then you can more accurately determine the key without a melody.
#3
i think in this situation it would be safe to say the key is Fmajor.

with Amin being the 3rd.

although, you could also say that Fmaj7 is the 4th and Amin is the 6th of Cmajor.
therefore rendering this Aminor....

so, as you say, it could be a few, and as the person above said, it depends on a few more things.