Who is the author of the book that has a musical adaption in which "Over the Rainbow" series in the United Kingdom was auditioning aspiring musical theatre performers for a role?
Over the Rainbow (Canadian TV series):  Based on the 2010 series "Over the Rainbow" in the United Kingdom, the series auditioned aspiring musical theatre performers for the role of Dorothy for a Toronto production of Andrew Lloyd Webber's stage musical adaptation of "The Wizard of Oz". The Wizard of Oz (1939 film):  Widely considered to be one of the greatest films in American history, it is the best-known and most commercially successful adaptation of L. Frank Baum's 1900 children's book, "The Wonderful Wizard of Oz."
L. Frank Baum