What happens when you change the pressure of your lips playing a brass instrument?

When you change the pressure of your lips playing a brass instrument, you are essentially changing the pitch of the sound. This is because the lips act as a vibrating reed, and the tension of the lips determines the frequency of the vibration. The higher the tension, the higher the pitch of the sound. This is why brass players use different embouchures (mouth positions) to produce different notes.

In addition to changing the pitch, the pressure of your lips can also affect the tone of the sound. A more relaxed embouchure will produce a softer, more mellow sound, while a tighter embouchure will produce a brighter, more piercing sound. This is why brass players use different embouchures to express different musical emotions.

The pressure of your lips is just one of many factors that affect the sound of a brass instrument. Other factors include the size and shape of the instrument, the type of mouthpiece, and the player's technique. By experimenting with different embouchures and other techniques, brass players can produce a wide variety of sounds and express a wide range of musical emotions.