Originally Posted By: VideoTrack
Originally Posted By: Mark Hayes
...Here I have a piece that begins with D#, continues to F#, then ends on F.

I called it key of Em, BIAB wants to call it key of Bb.

Why???

I'm guessing it's calling D#/Eb = IV and F = V and ignoring the F#?

I agree that the enharmonic Eb and the F could be contributing. Without knowing the algorithm, it's difficult to accurately guess, but no doubt we are working from the same page with this one.


I'm wondering what the musical basis of the algorithm would be.

Given nothing but those three chords – and forget about BIAB – would it be appropriate to analyze that piece in that way?

Specifically, does the presence of the IV and the V strongly imply the missing root, to the point where they determine the key?

This gets to questions about musical "reality" that are weighing heavily on my mind these days.