People like visit the Glastonbury Festival because it is the largest annual holiday celebrating of music and other arts. There are so many famous musicians who give live perfomances . Basically, because of favourite groups people go to the festival and sing fantastic songs.
Bands like taking part in such events as there they can be covered with the glory by their fans.
If I had a chance, I would definatelly visit this festival. It's much more interesting to listen to music in live concerts than with the help of special devices.