scoring

thumb|right|300px|A hand-written Sheet music|musical score for Act 2 of the [[opera Der Freischütz by Carl Maria von Weber, written in the 1820s. The score contains all the parts for the singers and the accompaniment parts and melodies for the orchestra.]] Orchestration is the study or practice of writing music for an orchestra (or, more loosely, for any musical ensemble, such as a concert band) or of adapting music composed for another medium for an orchestra. Also called "instrumentation", orchestration is the assignment of different instruments to play the different parts (e.g., melody, bassline, etc.) of a musical work. For example, a work for solo piano could be adapted and orchestrated so that an orchestra could perform the piece, or a concert band piece could be orchestrated for a symphony orchestra.

In classical music, composers have historically orchestrated their own music. Only gradually over the course of music history did orchestration come to be regarded as a separate compositional art and profession in itself. In modern classical music, composers almost invariably orchestrate their own work. Two notable exceptions to this are Ravel's orchestration of Mussorgsky's solo piano work Pictures at an Exhibition and Malcolm Arnold's orchestration of William Walton's String Quartet in A minor, producing the latter's Sonata for Strings.