So I have finished the A section of my waltz and am wanting to go to another key for the B section. The waltz is in the key of D major. So these chords are diatonic to it:
My melody in the A section ends on an F# as does the bass. This gives a sense that the section is finished but also that the key will change. Now, theoretically, there are 5 options to where to modulate to using that F#. But modulating to E minor I figured would be very unusual for a piece in D major without a previous modulation to G major. So that was out. This left me with 4 options. Those would be:
- F# minor
- G major
- B minor
- A major
The modulation to A major would be indirect. Modulating to iii I thought would be weird but it would be a common tone modulation because the note of F# is shared between the 2 keys. I have seen a ton of modulations to G major done via an F# rising to G. B minor would not be unusual at all, I would be doing a relative modulation there.
Someone else told me that because it harmonically makes sense, I should modulate to B minor. But why would this make more sense harmonically than say modulating to G major, the subdominant of D major, by raising the F# to G?
So which of these 4 keys I listed should I modulate to for my B section?