Orchestration

Orchestration is the study or practice of writing music for an orchestra (or, more loosely, for any musical ensemble) or of adapting for an orchestra music composed for another medium. Only gradually over the course of music history did orchestration come to be regarded as a compositional art in itself.

Orchestration as practice

The term orchestration in its specific sense refers to the way instruments are used to portray any musical aspect such as melody or harmony.

For example, a C major chord is made up of the notes C, E, and G. If the notes are held out the entire duration of a measure, the composer or orchestrator will have to decide what instrument(s) play this chord and in what register. Some instruments, including woodwinds and brass are primarily monophonic and can only play one note of the chord at a time. However, in a full orchestra there is generally more than one of these instruments, so the composer may choose to outline the chord in its basic form with clarinets or trumpets. Other instruments, including the strings, piano, harp, and pitched percussion are polyphonic and may play more than one note at a time.