The Wizard of Oz, that timeless classic from 1939, is the film of some of the most coveted pieces of Hollywood history. From the ruby slippers, to the Cowardly Lion’s suit, artifacts from this film continue to circle the world and draw crowds of all ages. A new piece of the film will be going on auction next month, but this artifact has a history of its own. The piece is a 300-year-old violin, and experts are estimating it could bring in as much as $20 million.