The valves are used to change notes.
Valves for brass instruments weren't developed until around the year 1800.
Yes, but there are trombones that do have valves. Bugles- no valves
They are called valves.
Not all brass instruments have valves. For example, the trombone has a slide. The trumpet, euphonium, and french horn have three valves.
Valves!
Brass instruments such as the trumpet, cornet, French horn and tuba.
I'm no brass instrument, but rotary valves are used for several instruments. French horns all seem to have them. They're pretty common on tubas as well. There are even some rotary valve trumpets out there. I don't know, though, anything about the advantages and/or disadvantages of rotary valves as opposed to the piston valves that seem to be more common for most brass instruments.
No, a saxophone has keys like other woodwind instruments. Brass instruments have valves.
Trombones are played by moving a slide, while other brass instruments use valves to change notes.
All the other brass instruments because they have valves.
Brass instruments can have valves or a slide, but not reeds. Brass instruments create sound by the vibrating of the player's embouchure in a mouthpiece, and the valves and slides on the instrument change the length of the tubing in the instrument which affects the pitch of the notes produced. Reeds are used in woodwind instruments to vibrate to produce a sound instead of using a mouthpiece like in brass instruments.
Brass instrument have valves to change the length of tubing that the air passes through. This allows the instrument to play different notes of various harmonic series.