The Internet gives us access to may cool tools and materials. We need to use them

 according to "fair use" guidelines.

Click here

Copyright explanation 

http://www.loc.gov/teachers/copyrightmystery/#

http://www.copyrightkids.org/

http://www.richmond.k12.va.us/schools/jones/Copyright-Kids/intro1.htm

As “Ten Common Misunderstandings about Fair Use" from the Temple University Media Education Lab says, "Applying fair use reasoning is about reaching a level of comfort, not memorizing a specific set of rules.” My personal "level of comfort" would permit me to use music in the way you have described without writing for permission. Here's why:

1. The use of the work is "transformative." You are using it for a purpose other than for which it was originally intended. You can describe your project as either "Personal reportage or diaries" or as a documentary.
2. Your use is non-commercial. I assume you are not charging students for the DVDs or admission to graduation ceremonies.
3. You are not effecting the potential market for the work. In fact, people might hear a song they like and buy a legitimate copy, in which the market impact would be positive.

One thing that I would consider doing would be to not use entire songs, but create a "medley" and only use music from the current year. This would strengthen the "documentary" aspect of the work as well as adding to the transformative nature of your use.

In Carol Simpson's database of reported cases of copyright lawsuits and cease and desist letters, I could not find an incident that is similar.

Check this site for Copyright info

http://memory.loc.gov/learn/start/cpyrt/index.html