Orchestration

Study or practice of writing music for an 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.

From Wikipedia, under CC BY-SA. More on occurri.