Hi! I've been playing from the book, "Advanced Lip Flexibilities" by Charles Colin. There are exercises in Volume 2 of the book called "Spreading Intervals". (For example, page 26: Spreading Intervals to E). When I play any of the intervals greater than one harmonic to the next, I hit all of the harmonics between the two notes. (Sounds like a glissando...) How do I best get rid of these middle notes? Thanks for your help!