I use this book in my ballet history course and it's a very good book for that purpose, that is, for a basic overview on the history of dance. You won't find many details on special subjects, such as specific ballets, but it's great if you want to understand the developement of ballet through the ages and know something about the people who put their marks on the ballet. Lot's of colour photgraphs. Au's use of words is sometimes a bit complicated, at least for someone who doesn't have English for a first language. But a great book.