Listening a lot to trumpet players like Arve Hendriksen lately who use a lot of air/breath along their normal sound. Terry Plumeri uses this in his bowing as well. What are the most important factors to get that air or bowhair 'noise' in your sound besides playing very lightly with less pressure of the bow and close to the neck? Want to able to have full control over the amount of air vs 'normal' sound.