Sandhofe + typo + rsigns according to Hartker and mora vocis

This should really call the simple 7th tone in ferias.

The issue is that the 7a (aka "mode D") invitatory psalm is recited on the final of the piece (I/ Populus Domini, ending on Ré, being considered as 7th mode transposed even though its modality is archaic/unclear), so employing it here with recitation on Ré and not on Sol would be modally incorrect (but melodically unproblematic...) - to be continued. Or perhaps the 7a tone is very much 7th mode, and the I/ Populus Domini is simply out of place.

Sandhofe's melody was checked against a number of diastematic sources. There are variants (French variant e.g. https://gallica.bnf.fr/ark:/12148/btv1b6000531z/f147.item has a torculus on (vigilan)TI(bus) and the classic 7th mode French formula on (domi)NUS (sol/la-do-sol/la-sol/sol-fa instead of sol-sol-fa) ) but globally, Sandhofe's melody is the best restitution that fits H.

NABC addivi