I have a few questions about the physics of the trumpet. 1) How does the tension on the embouchure change the resonance frequency of the horn? I understand that the trumpet tone is created by a standing wave created by the horn. Specifically, when a sound is initiated, the acoustical properties of the trumpet and atmospheric pressure, provide a reflection or feedback of a pressure wave which then sets the lip tissue into vibration. I also know that the frequency is determined by the alternating air current thru the Horgan, and not the pulsing of the lips. How then, does the tension of the lips, or aperture, change the pitch of the note played? 2) When playing high notes, what is the effect of the air suppled to the horn? I read somewhere that when playing high notes, the aperture gets small and tight fue to the added tension on the embouchure, and thus increasing the air pressure. Does this mean that we need to push more from the lungs to supoly more pressure to the air to play high notes, or you just need to release the air as you would do with the low notes, because the tension-added embouchure adds pressure to the air?