Who was originally cast for the voice of Shrek ?
Act I " Overture " – Orchestra " Big Bright Beautiful World " – Mama Ogre , Papa Ogre , Shrek " Story of My Life " – Guard , Fairytale Creatures " The Goodbye Song " – Shrek , Fairytale Creatures≠ " Do n't Let Me Go " – Donkey " I Know It 's Today " – Young Fiona , Teen Fiona , Adult Fiona " Welcome to Duloc " – Duloc Performers " What 's Up , Duloc ? "