4. Prince
In the same vein as Daft Punk; it is difficult to judge whether or not Prince will play Glastonbury this year. He is apparently notoriously difficult to negotiate with and will often only confirm his appearances at the last possible moment. At the end of the day though, he is a massive artist that had never played Glastonbury before. With five UK No.1 Albums to his name and more than 100 million albums sold world-wide it seems strange that he has never headlined before. In 2007 Prince played 21 nights in the 02 Arena so there certainly seems to be a large enough audience for him to play to. Since then though he has only played 1 date in the UK which was a headline performance at the Hop Farm Festival in 2011. He does not seem to play festivals very often although he did go through a little run of playing festivals that saw him headline Coachella in 2008 and Roskilde in 2010. Prince seems like an unlikely candidate, especially when we consider that he accused the festival of using his name for publicity in 2011. However, the fact he has never played before and he is rumoured to play every year means that he could be approached as an option.