Final answer:
Rosencrantz and Guildenstern try to cheer up Hamlet by arranging a musical performance by traveling actors.
Step-by-step explanation:
Rosencrantz and Guildenstern arrange a musical performance in an attempt to cheer up Hamlet. They believe that the performance by a group of traveling actors might lift his spirits. This activity is chosen as part of the court's efforts to distract Hamlet from his melancholic disposition and the perceived madness that has overtaken him since his father's death and his mother's hasty remarriage to his uncle, Claudius.