In the key of A minor you might be able to use both the E major and the E minor chords. Harmonizing the A natural minor scale gets a Emin, and harmonizing the A harmonic minor gets the E chord. I know this isn't what you asked about but I got to thinking about it when I read your question incorrectly. It might be useful to be able to find a theoretical reason why E-Emin might work in a song. I'm thinking anytime I see a major to minor chord switch I'll check and see if the chords in question are the V chords of the harmonic and natural minor scales.
2 2009-05-30 15:55:06
Re: One or Two Dominant 7th Chords, in the same song. (5 replies, posted in Music theory)
Thinking about the harmonized major scale, the dominant chord would normally be the V7 chord. In the key of G it would be D7 (D, F#, A, C). In the song you mention it looks like the D7 resolves to the chord that is a fifth below it, the G chord. The B7 (B D# F# A) contains a tritone between the D# and A. Typically the D# would resolve up to E and the A would resolve down to G#, just as the V7 chord did. The chord that comes after the B7 is C (C E G). It contains the E that the D# is pulling towards, but not the G#. This ought to leave that section of the song with a bit of unresolved tension, a feeling of mobility, which in this case makes sense because the truer, stronger resolution comes at the end when the D7 comes back to G.
I think. 