Cinderella and her Fairy Godmother sing in this song. Initially, the song focuses on what is impossible. Relating this to economics, Cinderella desires a point that is beyond the boundaries of her production possibilities frontier (PPF).
The way to obtain a bundle that is initially impossible to obtain is by obtaining or creating a new technology. Thankfully for Cinderella, this is exactly what happens when her Fairy Godmother works her magic.