A part is the music played by all or some of one instrument type in a polyphonic work. In some cases, one instrument type, such as violins or French horns, is commonly divided into two parts, each playing different notes. Parts can be for any number of players, ranging from a solo instrument, such as a solo violin or a single human voice, to a large number, such as the first violins section of a full orchestra or all the singers in a large chorus.
In full scores, each part is written on a separate staff, although a few instruments, especially the piano, are written on two staves. When performing, individual players generally use scores that contain only their own parts for ease of reading and to minimize page turning, rather than the much longer and more complex full scores.