How ballet has been transformed by choreographers from contemporary dance: 'It's an exciting time for the art form'

For a grand and stately art form, ballet can be very unpredictable. When I started writing The Ballet Lover's Companion, I knew that I'd have entries on the 19th and 20th-century classics, plus recent works establishing themselves on world stages. Then I found my history was expanding in both directions. I hadn't expected so many recent works to make the cut, or so many older works to leap back on stage after decades of neglect.