What is the meaning of "sostenuto" in music?

The term "sostenuto" in music refers to playing in a sustained manner. This indication typically instructs musicians to maintain the length of the notes, allowing them to resonate fully and produce a smooth, connected sound. This interpretation is essential for achieving the intended emotional effect of a piece, as sustained playing can convey different feelings and enhance musical phrasing.

In contrast, playing quickly and lightly, performing with exaggerated emphasis, or playing in a joyful manner has different musical implications and does not align with the meaning of "sostenuto." Each of those terms describes distinct styles and techniques that focus on various aspects of performance, such as tempo, articulation, or mood, rather than the sustained quality that "sostenuto" emphasizes. Thus, choosing the definition related to sustaining notes accurately reflects the intent behind this musical term.