I play a standard Bach Strad and I've been noticing more and more the flatness of the d and e above the staff. I just thought, since many players play fine despite this that I needed to practice more. However, I have no idea how to practice to raise the felt notes in tune. When I play forte they get in tune but the higher notes then get sharper. When I play more softly, I have more difficulty pitching the flat notes up. What kind of exercises are good for working on this?