I'm pretty clued up on music theory in general, but there's always been something that's bugged me slightly...
Say I wrote a progression that goes: Em / C / Dm / G for example...
What key would I say it's in? I know the parent scale is C Major because of the D Minor.
So what do I call it? It's not E Minor since the D Minor suggests it's from CMaj and not GMaj.
Basically, if a song starts on anything but the I or VI, what do you say the key is in?
Modally, it's E Phrygian I guess, but surely that's more down to the melody over the top, not the progression per say?
I think I made that more complicated that it needs to be :P