YOU MIGHT ASSUME that, once a trumpet has been made, the fundamental (its lowest note) remains at a constant pitch and your tuning problems are over. But you'd be wrong. Unlike a piano – where once it has been tuned, nothing can be done about pitch – with the trumpet, like all blown instruments whose metals are subject to external and internal temperature changes, tuning is a constant concern.
Tuning in itself is far more complex than simply 'getting the right notes'. The piano is tuned to a compromise set of pitches, which slightly alter the natural harmonic series. But all instruments that make their own pitches can select from a wider nuance of pitches. Sometimes a player will prefer a note that is slightly flatter or slightly sharper than the pitch on the piano. Breath, embouchure and some parts of the instrument (such as the mouthpiece) can achieve this.
Tony Cross explains how this is achieved on the trumpet, and outlines his views on buzzing (pressing the lips together and blowing through the small gap – often used as a warm-up exercise by trumpet-players).