Which term denotes a sound that is soft in music?

The term that denotes a sound that is soft in music is "piano." In musical dynamics, "piano" indicates that the music should be played quietly. It specifically instructs the performer to produce a gentle sound, contrasting with other dynamic markings that suggest greater volume. Understanding this term is fundamental in interpreting how music should be played or sung, as dynamics play a crucial role in conveying the emotional quality of a piece.

In comparison, "fortissimo" refers to a very loud sound, making it the opposite of "piano." "Pizzicato" describes a technique of playing string instruments by plucking the strings rather than using a bow, which does not inherently relate to the volume of sound produced. "Prestissimo" indicates a very fast tempo, unrelated to the softness or loudness of the sound. Thus, "piano" correctly signifies softness in music, aligning with its accepted use in these contexts.