Final answer:
The narrator likely refers to the boy as a 'bandleader' due to his role that mirrors the leadership and musical direction typically associated with a bandleader.
Step-by-step explanation:
In paragraph 1, the narrator most likely calls the boy a "bandleader" because the boy is depicted as taking on a role that is similar to a bandleader's in terms of musical leadership and influence. The term bandleader often implies a person who is in charge of a musical group, directing performances, and carrying the music forward. In the provided text, the boy may be orchestrating an event, leading an activity related to music, or simply showing traits associated with being the center of musical attention, such as confidence and control.