Amy writes:

I read a book in the early 80’s about some girls who go to a special boarding school for the arts. One girl is a painter, one a writer and one is a musician. At night, they are possessed by the ghosts of famous artists (one is T.S. Eliot) but are unaware of this. They find out the teachers are using them to get more works out of the dead artists. Do you have any idea what book this is? I have no idea of the name or the author.  Thanks.

 
Ooh, I know this one!

It’s Down a Dark Hall by Lois Duncan. One of my favorites!