What does the term "sultasto" refer to in string playing?

The term "sultasto" specifically refers to a technique in string playing where the musician bows lightly over the fingerboard, producing a softer and more delicate sound. This technique is often characterized by its ethereal quality, which stands in contrast to more forceful playing techniques that produce a brighter or fuller sound.

When applying sultasto, the bow is drawn in a lighter manner and positioned closer to the fingerboard than the strings, resulting in a sound that is airy and less direct. This is often used to create a particular mood or texture in music, making it an important technique for achieving specific artistic intentions.

The other options imply different playing techniques that do not align with the definition of sultasto. For example, playing at the bridge typically yields a brighter sound, and using heavy bow strokes is more about producing a full-bodied tone rather than a light one. Creating a percussive effect with the bow emphasizes a rhythmic and striking technique rather than the gentle, airy quality associated with sultasto.