Ghostly Music (Hippo Ghost S.)

All Beths ever wanted to do is play the piano. So an offer of lessons from the mysterious Megan seems like a dream come true.
But Megan's house is filled with a haunting music that only Beth can hear - and it has a powerful, dangerous effect on her. How can a piece fo music be making Beth ill? And who is the strange, ghostly girl in white who seems determind to keep Beth listeneing - whatever the cost?