It's a big issue, you can't use a music track by Robbie Williams or Don Maclean or any one else regardless of they are alive or not. You also can't use just a snip of the track, 30 seconds or less. You can't use other peoples music at all, ever! Even if they're your friend and you went to college with the lead singer of Blur! (which I did, sorry had to name drop)
But music does add a huge amount of atmosphere, meaning and depth to an animation or film project, so including it is crucial and also an important part of the process, so how do we get around this copyright issue?
Simple, make your own music. The animation below is a great example of a very simple sound track that was recorded with the voice over in about 5 minutes during a student teacher training day at Hope University in Liverpool. A student with very basic piano skills played the melody while another student acted out the voice over, perfect collaborative learning.
Use your student's music skills, or friends, family and work colleagues., if you want your film to have life outside the schools walls and be published or celebrated in the wider community.