Why does time stop when Cinderella steps on the black pitch?

Question

In Into The Woods, why does time stop when Cinderella steps on the pitch?

The Prince stops and the flames freeze, as you can see in the clip below.

Answer 1

The song is a plot point used to stop the action

When Cinderella becomes stuck in the pitch time doesnt stop straight away, only once the music starts and she begins to sing does the time stop, she then begins removing her shoes to escape the pitch.

Stephen Sondheim confirms in the below clip that songs are often used in Into The Woods to stop the action.

Time is stopped through the already established method of singing as a way the filmmakers get Cinderella to let the audience know her thoughts at that particular moment.