The native chord built on the 7th note of a major scale is a diminished chord -- In C: b, d, f. If you write it just as a vii, then most folks might play it as a minor chord -- b, d, f#. I guess you need to add that little diminished symbol to the vii symbol to ensure that it is played correctly (although some folks would try the vii as a diminished chord first).

Here's a link showing the chord symbols for the diatonic major scale/chords: C major, D minor, E minor, F major, G major, A minor, B diminished.




EDIT: Dang, I just noticed that BIAB uses all upper case for its roman numeral display. In C:
Cmajor = I, Dminor = IImin, ... , Bdim = VIIdim. That seems so non-standard to me.

Last edited by Kemmrich; 11/29/14 01:11 PM.
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