The Wizard of Oz (1902 musical)
The Wizard of Oz was a 1902 musical extravaganza based on "The Wonderful Wizard of Oz" by L. Frank Baum, which was originally published in 1900. Much of the original music was by Paul Tietjens and has been mostly forgotten, although it was still well-remembered and in discussion at MGM in 1939 when the classic film version of the story was made. Although Baum is the credited bookwriter, Glen MacDonough was hired on as jokewriter after Baum had finished the script.
Copyright status of The Wizard of Oz and related works in the United States
Thompson did not renew the copyright on her last five canonical books: "The Wishing Horse of Oz", "Captain Salt in Oz", "Handy Mandy in Oz", "The Silver Princess in Oz", and "Ozoplaning with the Wizard of Oz". Thus, these books entered the public domain 28 years after publication, between 1963 and 1967.
Congress amended the copyright law in 1992 so there would subsequently be automatic renewals of copyright. Therefore, the copyright on Thompson's deutero-canonical books "Yankee in Oz" (published in 1972) and "The Enchanted Island of Oz" (published in 1976) will not expire until 2068 and 2072 respectively.