How do a trumpet player’s lips produce a musical tone?

A trumpet player produces a musical tone through the vibration of their lips against the instrument's mouthpiece. This process, often referred to as using a "lip reed," occurs when the player presses their partially closed lips against the rim of the mouthpiece and blows air through them.1

As the lips vibrate, they create a tremor in the airflow that is transmitted into the instrument's tubing. The air column inside the trumpet then resonates at a frequency that matches the vibration of the lips. To control the resulting pitch, the player adjusts their embouchure—the specific positioning and tension of the lips in relation to the mouthpiece—to achieve the desired frequency.1

While the lips initiate the vibration, the trumpet's physical characteristics, such as the length of its tubing and the shape of its bore, further define the sound and allow the player to produce different notes within the harmonic series.21