The character known as "Bird" is a cuckoo visiting the protagonist during a late-night practice session. This cuckoo insists on practicing musical scales, specifically requesting to sing along with the cello's accompaniment. Though limited to its species' characteristic two-note call, their interaction becomes an exercise in aligning rhythm and pitch.

Initially irritated by the cuckoo's repetitive singing, perceiving it as a distraction, the cellist undergoes a shift during their extended duet. He begins to recognize the purity and precision within the bird's simple notes, ultimately feeling his own playing is inferior. This realization sparks frustration, leading him to impulsively chase the bird away. In fleeing, the cuckoo collides with a window, an incident the cellist later regrets.

The encounter proves instrumental to the cellist’s development. Through the repetitive exercise of matching the bird’s calls, he unconsciously hones his rhythmic consistency and intonation. The experience underscores the value of patience, attentive listening, and finding musical expression within technical limitations. While the cuckoo does not reappear, the cellist’s later remorse over his harshness reflects his growing empathy and artistic maturity. The bird’s role remains confined to this single narrative episode.