The cornets are the instruments that usually carry the tune in brass bands. Cornets come in various sizes.
Pitch depends on the length of tubing in the instrument.
The smaller the instrument, the higher its pitch. The pitch of a cornet is determined by the note it plays when no valves are pressed down. Valves allow the player to change the pitch. One flugelhorn to a brass band is the rule. The flugelhorn is in the same family as a trumpet and cornet.