-- maps sharp or flat scale over scale intervals from derivedModality
deriveScale :: String -> [String]
deriveScale a | isSharps a = map (sharps !!) (deriveModality a)
deriveScale :: String -> [String]
deriveScale a | isSharps a = map (sharps !!) (deriveModality a)
deriveScale a | isSharps a = map (sharps !!) (deriveModality a)