The White Ghost, Green Ghost and Black Ghost are conjured by Jack and Annie s magic violin in order to convince Mr. Dickens to keep writing by showing him meaningful scenes from his past, present and future. All three can be played by girls. Although the Black Ghost doesn t speak or sing, the actor needs to have a strong stage presence and must be able to stay focused and in character through the lengthy  Come Three Ghosts segment. The Ghost Chorus is made up of all of your ensemble  no need to cast a separate group of students in these roles.