I'm wondering if B means "si flat" or "si". I've studied "si" as H and "si flat" as B but everyone says that B is "si". Which is the right one?
It is a bit confusing if you are used to the German system where H is used. The English speaking people refer to H as B and they refer to B as B flat.
To my knowledge, accidentals don't affect the naming system. So the note association ignores the scale that it's in (if it's not a fixed system). If it's a fixed system (so it starts on C no matter what the scale), I believe it's B no matter what. Although, it's entirely possible it's a language by language system.