Musical Part is the name of each separate voice or melody, whose combination forms the harmony or the concert. To produce a chord, at least two sounds must be heard at the same time: something a single voice could never do. To form a harmony or a chord progression, many voices are therefore necessary: the melody that belongs to each of these voices is called a part , and the collection of all the parts is called a score . See Score.

As a complete chord is composed of four sounds, there are also four principal parts in music, of which the highest is called, soprano, and is sung by the voices of women, children, or musici ; [1] the three other parts are the haute-contre, the tenor, and the bass , which are all voices of men. One can see in our Plates on Music the range of the voice of each of these parts , and the clef used for each. The half notes show the full-voice pitches each part can reach, both high and low; and the eighth notes that follow, show the pitches where the voice begins to strain, and that it can produce only in passing.

Many of these parts subdivide in two, when one composes for more than four parts. See Soprano, Tenor, Bass, Voice.

There are also instrumental parts . There are even some instruments, like the organ, the harpsichord, and the viol, that can play several parts at once. In general, one also divides the instrumental music into four parts , which correspond to those of vocal music, and that are called dessus, quinte, taille , and basse . One will also find their clefs and range. Plates on Music. But it is necessary to note that most instruments do not have precise limits in the upper register, and that one can make them go as high as one wants, at the expense of the ears of the listeners; whereas in the low register they have a fixed limit that one cannot exceed, which is the pitch that I have indicated.

There are some parts that should not be sung except by a single voice, or played by a single instrument; and these are called solos [ parties récitantes ] .  [2] Other parts are executed by many people, singing or playing in unison, and one calls them choruses [ parties de choeur ].

Part also refers to the paper on which the separate part of each musician is written. Sometimes several sing or play from the same paper; but when they each have their own, which is ordinarily done in music for large ensembles, one can say in this sense, that there are as many parts as there are performers.

1. Musico / musici is a polite circumlocution, used in Italy and Britain, for the Italian word castrato / castrati.

2. The French noun “récit” and adjective “récitante” are faux-amis or false cognates: they mean “solo” and have very little to do with the Italian opera term “recitative” or its French equivalent “Récitatif,” which Rousseau defines in the article Recitative.