Why was Brian May, guitarist with the band Queen, appointed chancellor of a major learning institution, a post he held for 5 years?

Although Brian May has a Ph.D in astrophysics, which he was awarded in 2007, his post as chancellor of Liverpool John Moores University (LJMU, which he held for a five-year term from 2008 to 2013) was a ceremonial position, calling for him to act as a promoter for and a representative of the university. According to the attached press release, he completed some of the academic work for his Ph.D on a telescope in the Canary Islands owned by LJMU.

His predecessor in the position was the British lawyer Cherie Blair (1999-2006), better known as the wife of then-U.K. Prime Minister Tony Blair.
https://en.wikipedia.org/wiki/Chancellor_of_Liverpool_John_Moores_University
https://web.archive.org/web/20100906210108/http://www.ljmu.ac.uk/NewsUpdate/index_92016.htm