Final answer:
Music is a personal choice and a form of arts that connects deeply with human emotions. An instructor prompted students to share their favorite songs to engage with the subject matter.
Step-by-step explanation:
The subject here is music, which is a form of arts. When discussing favorite songs or pieces of music, it is a very personal choice that can vary greatly from person to person. However, it is interesting to note that music, much like literature and other forms of entertainment, can provide insight into what makes us human and can influence our emotions and thoughts. In the context of the question, where a lesson or unit is about to begin, the instructor has shared their favorite song, "Happy" by Pharrell Williams, and encourages students to think about their own favorites as a way of engaging with the subject matter on a personal level.