What does 'pedale' or 'ped.' refer to in musical notation?

In musical notation, 'pedale' or abbreviated as 'ped.' specifically refers to the use of the pedal, particularly in keyboard instruments like the piano. The pedal allows performers to sustain notes and create a more connected sound by enabling them to continue to hold down one or more keys while also playing other notes. The indication to use the pedal signals the musician to engage the sustain pedal to enhance the expressive quality of the music. This practice can change the texture and mood of a piece by blending sounds and extending the resonance of the notes played.

The other options pertain to different musical expressions or techniques. For example, playing softly is indicated by terms like 'piano,' while emphasizing notes is often denoted by markings such as 'fermata' or 'accent.' Rapid playing is typically indicated by terms like 'allegro' or specific tempo markings. Thus, 'pedale' is distinctly linked to the action of using the pedal rather than any of these other musical directives.