Actually I wasn't. Had to look up the meaning of this. Seems quite appropriate though for a 15th century Carol. Many thanks for all your suggestions: they were super helpful! I should've spotted that A flat in b.30. It's really obvious now you've pointed it out! Decided to go with no key signature, since there is no settled key, and have attached a revised version below. I couldn't get the breath marks to work properly in MuseScore: so I left them out. (They appeared right on