A commenter on YouTube just noticed a glaring mistake in one of my videos (well, a whole series of videos).
The original When Johnny Comes Marching Home is minor, not major. Which I really should have noticed just by listening, or at least by doing a quick search.
The way I create the retuning videos depends on the original being in C Major. C Major is identified by having no sharps or flats in the key signature (and ideally for my process by having no sharps or flats at all).
Of course, the whole point of the videos is there are in fact seven different modes that might actually be used in a piece with no sharps and flats. In practice, five of them are unlikely to be used. Aeolian however is pretty common - especially using its more common name of natural minor. This concept even has a name: the relative minor.
The net result is the names of all the modes in the When Johnny Comes Marching Home videos are incorrect. The original is not in C Major for example but A Minor (or A Aeolian). The one supposed to be in C ascending melodic minor, is in fact in A half-dminished. *
I will upload correct versions shortly. I need to expand my process to handle pieces that are not originally in a major key however (something I intend to do anyway).
* The original was not actually in A minor but G minor, but that was intentional. Simple transposition does not affect the modes.