What does "tacet" instruct musicians to do?

The term "tacet" is used in musical scores to indicate that a particular instrument or voice should remain silent for a specified section of the music. This instruction is essential for ensemble pieces where certain instruments or voices are expected to pause while others continue playing. By indicating silence, "tacet" allows musicians to contribute to the overall texture of the piece without producing sound during that specific moment.

The other options do not accurately capture the meaning of "tacet." Playing softly, increasing volume, or playing faster would all involve sound production, which contradicts the purpose of the instruction to be silent during that section of the music. Thus, the correct understanding of "tacet" is fundamental for interpreting and performing a score accurately.