Julie Andrews, who played Maria, and Christopher Plummer, who played Captain Von Trapp, were joined by the seven actors and actresses who starred as their children in the 1965 film.
While Plummer revealed that he had a secret crush on Andrews while they were making the musical, while Charmian Carr – who played Liesl - confessed that she had the hots for her on-screen father.
'I got to stay in the hotel with Christopher Plummer because I was an adult. I learned how to drink,' she laughed.
'I had a huge crush on him. He was so perfect and he spoke with this perfect British accent.'
The Sound Of Music cast came together on The Oprah Winfrey Show to mark the 45th anniversary of the much-loved movie.
Kym Karath (Gretl), Duane Chase (Kurt), Debbie Turner (Marta), Nicholas Hammond (Friedrich), Angela Cartwright (Brigitta) and Heather Menzies-Urich (Louisa) joined Andrews, Plummer and Carr to lift the lid on the musical's best-kept secrets.