What is "tacet"

Tacet \Ta"cet\, v. impers. [L., it is silent, 3d pers.pr. of tacere to be silent.] (Mus.) It is silent; -- a direction for a vocal or instrumental part to be silent during a whole movement.

musical instruction, 1724, from Latin tacet "is silent," third person singular present indicative of tacere (see tacit).

vb. (label en music) instruction indicating silence on the part of the performers of a piece

Tacet is Latin for "it is silent". It is a musical term to indicate that an instrument or voice does not sound. In vocal polyphony and in orchestral scores, it usually indicates a long period of time, typically an entire movement. In more modern music such as jazz, tacet tends to mark considerably shorter breaks. It was common for early symphonies to leave out the brass or percussion in certain movements, especially in slow (second) movements, and this is the instruction given in the parts for the player to wait until the end of the movement.

It is also commonly used in accompaniment music to indicate that the instrument does not play on a certain run through a portion of the music, i.e., "Tacet 1st time." The phrase tacet al fine is used to indicate that the performer should remain silent for the remainder of the piece (or portion thereof), and need not, for example, count rests.