Which finger technique does 'bisbigliando' emphasize?

The technique known as 'bisbigliando' emphasizes quickly alternating between two fingers. This creates a unique fluttering sound that is characteristic of this technique, often used in string instruments like the violin or the guitar. By rapidly switching back and forth between the two fingers, musicians can produce a shimmering effect that adds texture and expression to the music. This means that while using multiple fingers is a relevant aspect, the specific action of alternating between just two fingers effectively captures the essence of 'bisbigliando.'

In this context, the other options do not align with the technique's definition. Using multiple fingers rapidly suggests a broader use that isn't specific to the two-finger alternation, while applying a single heavy finger focuses on weight rather than agility. Similarly, using the whole hand for a broad stroke diverges from the delicate, rapid motion that defines bisbigliando.