What does a 'fermata' indicate in music notation?

A 'fermata' in music notation is a symbol that indicates the performer should hold a note or a rest longer than its usual duration. This symbol often looks like a dot with a curved arc over it and signals to the musician to take a pause that is typically longer than the standard value of the note being held. The specific duration is usually left to the discretion of the musician, often depending on the context of the piece or the conductor's instructions. This technique enriches the music by allowing for expressive interpretation and adds a dramatic emphasis to the held note.

In contrast, the other options pertain to different musical directives. Playing a note softer refers to dynamics and would be indicated by terms such as "piano" or "p." Repeating a section is denoted by symbols like "D.C." (Da Capo) or "D.S." (Dal Segno), while gradually slowing down is specified by the term "ritardando." Each of these serves a unique purpose in musical notation, distinct from the function of a fermata.