Which of the following is associated with a gradual build-up in volume?

The term that describes a gradual build-up in volume is crescendo. When musicians see a crescendo notated in the music, it instructs them to gradually increase the loudness of the notes being played or sung. This technique is commonly used to create tension, excitement, or a climactic moment in a piece, enhancing the overall emotional impact of the music. The crescendo can be indicated through various notational symbols, such as a wedge shape that opens towards the right.

The other terms listed refer to different musical techniques. Decrescendo indicates a gradual decrease in volume, while ritardando means to gradually slow down the tempo. Staccato, on the other hand, refers to a style of playing or singing where notes are performed sharply and detached. Understanding these terms helps musicians apply the correct techniques effectively in their performances.