Mary Poppins: From Page to Stage (2009)

Behind the scenes look at the creation of the stage musical. Filmed in the UK, France, and the United States, it features a series of conversations with many of the show's creators including producers Cameron Mackintosh and Thomas Schumacher, composers George Stiles and Anthony Drewe, Richard Sherman (who co-wrote music and lyrics for the original film), and set and costume designer Bob Crowley. The documentary also features a roundtable discussion at Sardi's restaurant between Schumacher and actors Ashley Brown and Gavin Lee, who originated the roles of Mary Poppins and Bert in the Broadway production.

Unfortunately the movie Mary Poppins: From Page to Stage is not yet available on HBO Max.