The orchestra consists of several instruments, each of which plays a unique role in order to render all the dimensions of a musical work. In general, there are several families of orchestral instruments, such as woodwind instruments, brass instruments and string instruments.
Wind instruments are all musical instruments whose sound is produced by the vibration of a column of air. This can be obtained in different ways: by the musician's breath (e.g. the flute), mechanically (e.g. an accordion) or by an air pocket (e.g. a bagpipe).
Wind instruments are grouped into two large families: woodwinds and brass. Contrary to what one might think, it is not the material in which the instrument is made that defines its category - even if this was once the case - but rather the way in which the sound it emits is produced.
Wind instruments can be made of wood, plexiglas, metal, plastic, ivory or even crystal.
In an orchestra, the wind instruments are normally located in the center, to highlight their particular sound. Often soloists, they bring a different timbre and add more colors to the orchestra.
String instruments produce sound by the vibration of one or more strings, not by air. The vibration is then amplified by a soundboard which can take various forms, depending on the type of instrument.
There are three types of string instruments: plucked (such as the harp or guitar), struck (such as the piano) or rubbed (such as the violin, cello or double bass).
The bowed string instruments form the sound basis of the classical or symphonic orchestra. The arrangement of the instruments within the orchestra will change the rendering of the musical work. Several patterns are possible, but as a general rule the first violins are placed in the first row on the left and then the other strings in a semicircle to the right, from the highest to the lowest.