Dorian should NOT have the same key sig as natural minor. Natural minor is Aeolian.
Exactly. I mean, we don’t need special key signatures for modes anyway. They already have key signatures. Major and minor keys are perfectly adequate.
This is venturing into crutch territory like the billions of “practice” ideas about weird patterns and shapes for scales. Just learn the friggin scale up and down the neck. Done. Same with key signatures and sheet music. Play the piece as written and if it happens to center around a mode, fine. All you need to really understand is the key and harmony if you happen to be improvising over it later.
