1. Length of the air column: The longer the air column, the lower the pitch of the sound. This is because the longer it takes for the sound wave to travel down the air column, the longer the wavelength of the sound wave.
2. Embouchure: The way the air is blown across the mouthpiece also affects the pitch of the sound. A tighter embouchure produces a higher pitch, while a looser embouchure produces a lower pitch.
The flute has a number of keys that can be opened and closed to change the length of the air column. When a key is opened, the air column is shortened and the pitch of the sound is raised. When a key is closed, the air column is lengthened and the pitch of the sound is lowered.
The flute also has a number of different embouchures that can be used to produce different sounds. A player can change the embouchure by changing the way they hold the flute, the way they blow air, or the way they shape their lips.
By combining different fingerings and embouchures, a flute player can produce a wide variety of different sounds.