There is only one subject matter for education, and that is Life in all its manifestations.
Karaoke as a teaching tool
Check out this cool story from NPR about using karaoke to teach about water pollution in Cambodia. According to the website:
Drinking water in Cambodia carries many risks. Many of the nation's wells and rivers contain bacteria, parasites and pesticides. However, there are ways to avoid unsafe water. Villagers are learning about safe drinking water through karaoke videos that combine stories of love with information about the dangers of arsenic and bacteria in some hand-dug wells.
If you listen to the story, Mickey Sampson of Research Development International (RDI), the originator of the idea, explains that the most effective way to get these messages across was through a form of media that people already enjoyed. As explained in the FAQ on RDI's website: “While Americans might find an educational song to be ‘cheesy’ or less than desirable, RDI has found that audiences are eager to sing our educational songs because of the very high quality in which they are written, played, and vocalized.”