What do the valves on a french horn do?

The valves on a french horn are used to change the length of the tubing within the instrument, which alters the pitch of the notes produced. The french horn has three valves, each of which is operated by a finger of the player's left hand.

* The first valve lowers the pitch of the instrument by a whole tone (two semitones).

* The second valve lowers the pitch by a semitone (one half step).

* The third valve lowers the pitch by a third (three semitones).

When multiple valves are pressed down simultaneously, the pitch is lowered by the sum of the individual valve changes. For example, pressing down the first and third valves together lowers the pitch by a minor third (three semitones + three semitones = six semitones).

The valves on a french horn are also used to play certain notes that would not be possible to produce otherwise. For example, the note "F#" can only be played by pressing down the first and second valves together.

The valves on a french horn are an essential part of the instrument, and they allow players to produce a wide range of pitches and notes.