Brass instruments are a family of musical instruments that ceate sound using a cupped or conical mouthpiece pressed against a player's lips. The lips vibrate against the mouthpiece, causing sympathetic vibration of the air inside the horn. Because the player's lips are integral to the production of sound, brass instruments are also known as "labrosones."
The brass family can be broken down into four sub-categories: valved, slide, natural, and keyed.
Valved Brass Instruments
Trumpet, cornet, flugelhorn, mellophone, French horn, alto (tenor) horn, baritone, euphonium, tuba, and sousaphone. While piston valves are most common, rotor valves may also be used on any of these horns but are most common on French horns and tubas.
Slide Brass Instruments
Trombones are the primary slide instruments in use today. The trombone differs from valved brass instruments because it uses a main slide instead of valves to change the harmonic series of the horn. Fun fact: all brass instruments are technically slide instruments because they all use tuning slides for fine-tuning. Only the trombone, though, uses a main slide to change the harmonic series.