I should have specified a GM7 chord, sorry.
Where you are playing in a C scale, and C is I and G is V.
Construct a M7 chord for C, play it. Construct it the same way using G as the root, and it produces a F# which is contrary to the C scale.
Basically, is would it be absolutely incorrect to ever use a GM7 chord, while playing in the key of C?
Although I am quite interested in what you mentioned about using a different mode for accompaniment- could you suggest how I could find more good information on this?
I just don't understand how the Aerith theme that I mentioned has A#, G#, in addition to F#, C# that you mentioned, and every single white note.
'My favorite things' is commonly played in G but also has a D# and C#.
'The Entertainer' has G# D# A# F# plus every white note minus F.
These are all songs that are fairly common to western culture, would they all really be in bizarre scales or is there something else going on?