Luis milan parvanas idioms

Eric, I am not a Renaissance Theory expert by any means - my background is primarily in Common Practice Period harmony.

But, from what I can surmise:

The section with all the "C" cadences is the Hypodorian section.

We're transposed up a 5th here, so the Dominant of Hypodorian, originally F, is now C. In my experience, the "ambitus" isn't usually take literally. The Dominant and Finalis are more important in determining mode (and there are pieces that don't even end on the correct Finalis!).

As far as the C#s and G#s this is COMMON.

Think about modern minor: A Minor has no sharps or flats in its key signature, yet you'll see G# all the time.

This comes from the evolution from the modal system.

Each mode that did not contain a half step from the 7th note to the Final used a raised 7th note at cadences - what we call the "Leading Tone".

That means, in A Dorian,