Glastonbury Abbey, King Arthur and Gregorian Chant

I'm starting research for my next historical novel and I've been musing on things medieval. A friend dropped by the other day with a book about the Glastonbury Abbey, a most holy and beautiful place of ruins (blast you, Henry VIII and your greedy minions!). Way back in pre-history, apparently, there were settlements in the area, and it is thought that Druids held ceremonies there in the centuries before the Common Era. By the time the Romans came and went, and Christianity took over, there were hermits and holy folk assembled in small huts on the Glastonbury Plain, which eventually grew into a huge monastic community that lasted well into the 1500's. Absolutely fascinating reading. Sometime in the 1200's, a gravesite was dug up and the remains of a tall man and a blonde woman were unearthed - determined by the abbot at that time to be King Arthur and Guinevere. They were reverently re-buried, but then that darn Henry VIII 'reformed' everything and the grave was despoiled. There's only a plaque there now. Another section of the book talks about the music at the Abbey, and how one of the abbots tried to replace the popular Gregorian chant with "new" music of the day, and wasn't very successful. I'm going to have to dig up my old chant CD's and play it as background while I attempt to start a new novel.