What do the slides on french horn do?

The slides on a french horn are used to change the pitch of the instrument. By moving the slides in and out, the player can change the length of the tubing, which in turn changes the pitch. The slides are also used to create vibrato, by slightly moving them back and forth.

The french horn has three slides: the main slide, the upper slide, and the lower slide. The main slide is the longest slide and is responsible for the most significant changes in pitch. The upper and lower slides are shorter and are used to make smaller adjustments to the pitch.

The slides on a french horn are an essential part of the instrument and allow the player to produce a wide range of notes.