Many years ago, some composer had the bright idea to write a piece of music for a large group of musicians, and they called this group an orchestra. In those days, a large group meant only a dozen or so, but since then orchestras have grown, and a modern orchestra may have over a hundred instruments.

The orchestra is divided into four sections:

The Woodwind

Woodwind instruments are made of wood, except those which are made of metal. They are instruments in which the sound is produced by a vibrating reed, set in motion by the player's breath. The four principle instruments are Flutes, Oboes, Clarinets and Bassoons; there are also auxiliary instruments such as the Piccolo (a little flute), the English Horn (neither a horn nor English but like a big oboe), the Bass Clarinet and the Contrabassoon.

The Brass

Brass instruments are made of metal, but they don't have to be: the obsolete Serpent was made of wood, and the earliest instruments were hollow animal horns. They are instruments in which the sound is produced by the vibrations of the player's lips against the mouthpiece. The four types of instrument are Trumpets, Trombones, Horns and Tubas, but there are many others such as the Euphonium (a little tuba), the Cornett (a bit like a trumpet), the Sousaphone (which goes right round the player's head) and the Wagner Tuba (more like a horn than a tuba). The Saxophone is actually a woodwind instrument, related to the clarinet.

The Strings

Stringed instruments are generally made of wood, with the strings made of gut or metal. Sound is produced by drawing a bow across the strings, or plucking them with the fingers. The four types are Violins, Violas, Cellos and Double Basses. The first three are the Violin Family, and are quite similar to each other: violas and cellos are basically violins scaled up. Although it has the least types of instrument, the string section is the largest in the orchestra, with as many as a dozen players to each part, and the violins are almost always divided into two large groups.

The Percussion

Percussion instrument are instruments in which the sound is produced by means of being hit. There are too many types to list, some common ones being the Bass Drum, Side Drum, Tenor Drum, Timpani (or Kettledrums), Cymbals and Triangle. Some pieces require quite bizarre percussion: Chain, Anvil and Wind Machine are among the more well-known. The percussion section can basically include anything which can't run away during the concert.

The orchestra is directed by a conductor who stands on a little platform, waves a stick, and gets his name on the programme.