Arnstein v. Porter
Cole Porter was among the most famous songwriters of the early twentieth century. The plaintiff in this case, Ira Arnstein, alleged that he had written several of Cole Porter's songs, including Don't Fence Me In, Begin the Beguine, I Love You, Night and Day, and You'd Be So Nice To Come Home To. Columbia Law School has an excellent page that contains music clips of both Arnstein's and Porter's music.
At the time Arnstein filed the case, Don't Fence Me In was one of the most popular songs in the country. It was originally used in the movie Hollywood Canteen, which has an interesting back-story. The movie is based on a real Hollywood bar that was founded and staffed by movie stars, including Bette Davis, that catered to servicemen during WWII. The bar closed in 1948. A later bar in LA used the name, but has now closed.