What does a "stressed note" refer to in music?

A "stressed note" in music refers to a note that is given emphasis, typically making it stand out from the surrounding notes in a musical passage. This emphasis can be achieved through various means such as playing it louder, longer, or with a different articulation. The purpose of stressing a note is to draw the listener's attention to it, creating an important moment within the piece.

In contrast, the other choices represent different musical concepts that do not align with the definition of a stressed note. Playing a note softly would imply a lack of emphasis, and extending a note pertains to its duration rather than its stress level. Muting a note, on the other hand, involves dampening its sound, which also contradicts the idea of emphasizing it. Therefore, emphasizing a note is essential in expressive performance, shaping the musical narrative, and enhancing the overall emotional impact of the music.