Orchestration is the art of writing music for the orchestra, deciding which instruments play which lines and how they combine. A skilled orchestrator understands the range, tone color, technical capabilities, and blending properties of every instrument.

The same musical idea can sound radically different when given to strings, to woodwinds, or to full brass. Orchestrators choose these colors to support the emotional and structural needs of the piece. They also consider balance so that important lines are not covered and the overall texture remains clear.

Some composers orchestrate their own music; others work with specialist orchestrators, especially in film and musical theater. Studying the orchestral scores of masters remains the best training. Effective orchestration can make a simple idea sound rich and a complex idea sound transparent.

The best orchestrations feel inevitable, as if the music could not have been scored any other way.