Music for a melody instrument such as a violin or a trumpet is written on one staff; keyboard instruments require two — one staff for the right hand, another for the left hand. Music for two or more voices or instruments, choirs, bands, and orchestras is written in scores. In scores, each instrument and voice that has its own independent music gets its own staff. Simultaneously sounding notes and measure lines are aligned vertically. In general, high-sounding instruments go on top, the low ones on the bottom.

Shown below is a page from Mozart’s “Jupiter” Symphony, with arrows pointing to the various details of notation that have been explained above.