Brass

Like the woodwinds, the name of this section is derived from the original metal used to make the instruments, however today pure brass instruments are rare. In the modern orchestra we can usually find 4 horns, 3 trumpets, 2 trombones and 1 bass trombone, and a tuba.

The distinguishing features of brass instruments are their flaring bell and their valves. The valve system was developed in 1815 to enable players to quickly change the length of the vibrating air column and thus the pitch of the note produced, instead of having to use more cumbersome solutions such as the olden-day crooks (lengths of metal tubing).

Sound is produced, as for all wind instruments, through the vibration of air in the hollow metal tube. This is achieved by vibrating the lips as the player blows, in a fashion somewhat similar to the use of a double reed. The pitch can be affected not only by the length of tubing, but also by the tension of the player's lips - the tighter the player's lips, the higher the note.

The timbre of brass instruments is unique, ranging from the brilliant fanfare of the trumpets to the sonorous bellows of the tuba. This is to some extent influenced by the bore and the bell. Apart from the construction of the instrument, players may also insert a mute which muffles the sound produced, or, if the player continues to attempt to force the sound out, creates a metallic, menacing tone.