The techniques to hit high notes on the tuba require a proper understanding of breath control and the embouchure. The embouchure consists of the way in which the muscles and lips form to direct the flow of air through the mouth. When air flows through tensed lips, vibrations are formed, which are then carried through the tuba. Faster vibrations will create higher notes but to create faster vibrations, the muscles in the face must be strengthened.
One method to increase your high range is to develop proper breathing habits. A tubist who is not able to maintain a large amount of air will have trouble playing the highest notes in the tuba literature. To breathe properly, inhale as if you were yawning. Your sides will expand and your stomach will push outward. Control the airflow with your diaphragm muscles and the muscles of your abdomen to push the air out with a quick and controlled stream of air.
Start on an F in the middle of the staff, and play the following rhythmic pattern at 60 beats per second: half note, half note, whole note. Then, breathe in through the nose for four beats, and continue the sequence a half step higher on F-sharp. Continue adding a half step each time, and don't remove your mouth from the mouthpiece. Keep your cheeks tucked in and not puffed out. Use a narrow and quick airstream. Once you have reached the highest pitch you can play, rest for 20 minutes, then start three pitches below the highest pitch you played previously. Attempt to exceed your highest pitch and stop.
Play long tones in the high range. Start with a B-flat above the staff and ascend by a half step to B. Hold each note for four beats, then descend to the high B-flat and hold it for another four beats. Rest for two beats, then play the series again, each time adding a half step. The next two sequences will be B-flat to C to B-flat, then B-flat to D-flat to B-flat. Continue this series until you cannot play any higher to help strengthen your embouchure.
Play slurs using each valve combination to loosen up and strengthen your embouchure. Start with all valves open, and play an F. Jump up to the next nearest open valve note; in this case, it is B-flat. Then jump back down to the F. Now, jump up an octave, then down to the B-flat and back to the original F. Continue this sequence on every valve combination, moving from open to second valve to first valve; then first and second valve; then second and third; followed by one and three; and ending on valves one, two and three.