Why is it in counterpoint that the fourth degree of natural mode "F" lowered to "Bb" instead of remaining as "B"? Why isn't the fourth degree lowered for other modes? Shouldn't the "B" remain natural if composing within the natural mode of "F"? Why does go outside the natural mode?
Transferred from: Few Questions on Counterpoint in the Tradition of Johan Fux
Not a duplicate, but similar to: Accidentals in First Species Counterpoint