I will group the “Old School” approach to improving high range as any method using traditional methods which would include improvement one half-step at a time over a period with constant repetition. The highest note in the entire Arban Method is only a high C. Did you ever wonder why this appened.? Why was such a popular and authoritative work so limiting in the upper register? I’m not sure anyone would have the real reason for many factors affected the material at that period of time. It is interesting to read the review of  Arban’s material when he submitted it…