PLAYING IN THE UPPER REGISTER
There is a systematic approach to playing high notes on a consistent basis. The four most important aspects are: (1) High Pressure Air Tank (2) Tongue Position (3) Lip Position (4) Super Fast Air Stream
(1) First, you must have air the reserves ready to be called up at a moments notice. I believe that the type of air needed to play lead is most closely related to a High Pressure Air Tank. You must tank up on a small quantity of high pressure air and release the valve, releasing the Super Fast Air Stream. When playing lead one should ride this high pressure air stream. Let the High Pressure Air Tank and the subsequent Super Fast Air Stream help do the work. It's not the QUANTITY of air, but the SPEED of the air stream. VERY IMPORTANT: Playing high notes actually requires quite a small quantity of air.
(2) Next, Tongue Position should also be addressed. Saying ‘ah’ lowers the tongue and increase the ‘VOLUME’ of air. We don't want volume, but a Super Fast Air Stream. Saying ‘ee’ arches the tongue and 'INCREASES AIR SPEED' for high note playing.
(3) Lip Position. Imagine you have a tennis ball in your fingertips - now squeeze! This squeeze or pushing of your lips together is needed to play high. I personally use what people have called the ‘Superchop Method’ I pivot to push the lips over the top teeth and arch my tongue to alter the air stream. My lower lip curls in over the top of the bottom teeth. The top lip slightly overlaps the lower lip. The lip compression comes from pulling all of the muscles in toward the center.
(4) Finally, one must use a Super Fast Air Stream. The key is to achieve an incredible velocity of air, not quantity. The velocity must be so fast that it screams through the horn like a Mach 4 fighter jet. I mean fast! You should not puff your cheeks at anytime, check in a mirror. If you are puffing your cheeks, take your hand and literally hold your checks in, until your muscles are strong enough to do it on its own. Your goal is to obtain this Super Fast Air Stream INSTANTLY. It is the air speed, combined with lip and tongue position, that will give you success in the upper register.
Using the Air Tank, Tongue Position, Lip Position, and Air Speed YOU must also practice high note playing EVERYDAY. I often take the Clarke Studies up to the next octave for practicing. Or perhaps you could practice the leads to your favorite big band or pop charts. Either way, nothing happens without practice and hard dedicated work.
Below is a pdf of the High Note High Range Playing Chapter from the Ultimate Warm Up Book.