So I was thinking this would look really odd. Do you have to use the same format as you introduce a spoken part, or can you do this? And what might be the alternatives to this? I am asking, because this looks really odd.
"This is wild!" she said. "Really wild!"
She then decided to sing:
Cruella de Vil, Cruella de Vil!
If she doesn't share you, no evil thing will
To see her is to take a sudden chill
She's like a spider waiting for the kill
Look out for Cruella de Vil.