Why does the tricuspid valve have three flaps?

The Trumpet has three valves to change the pitch. Each valve actually makes the trumpet longer, which lowers the pitch.

In order from shortest to longest:

* The Second Valve lowers the pitch 1/2 step (one key on the piano, such as from G to F#) * The First Valve lowers the pitch 1 whole step (two keys on the piano, such as from G to F, or from C to Bb). * The Third Valve lowers the pitch 1 and 1/2 steps (three keys on the piano, such as from G to E, or from C to A). The valves can be pushed in combination to lower the pitch further. For example, pushing the first and third valves would lower the pitch 2 and 1/2 steps, or from G to D on a piano keyboard.