you could spend maybe 5 minutes talking about subliminal messages in disney movies.
you could probably go on for a while talking about the psychology behind disney movies. instilling kids with the fear that their parents are going to die, etc.
if i were you, i'd probably just do hip-hop. start at jamaican dub and work your way up through the modern day. after the big split in the 80's, a lot new genres started and you could go talk about those for a while. hip-hop has some really rich history.