The Baroque Trumpet -  also called the natural trumpet.

The natural/Baroque trumpet is the predecessor of the modern trumpet. However, the natural/baroque trumpet has no valves, and can only play notes which belong in the harmonic series. This means that the player has to change the tubes of the instrument to play in a different key, and a lot of notes do not exist on the instrument. The trumpet was used as a signal instrument at first, but later also became popular within the concert halls and in symphony orchestras.