score
The written form of a musical composition showing all parts simultaneously.
In Depth
A full score displays every instrumental and vocal part of a composition on vertically aligned staves, allowing the reader to see what every performer plays at any given moment. Orchestral scores can have 20 or more staves per system, with instruments arranged from top (woodwinds) to bottom (percussion, strings).
Conductors study full scores to understand how all the parts interact. A miniature score is a reduced-size version for study purposes. A piano reduction condenses an orchestral score onto two staves. Individual performers read from parts — extracted single-instrument versions of the score. The skill of score reading — hearing the music mentally by looking at the full score — is one of the most demanding musical abilities.
Mozart could reportedly hear an entire orchestral score in his head just by reading it — and could write out full scores from memory after a single hearing of a performance.