I need a good song to sing, that will help my new pet to feel safe and come out, suggestions?

I just got myself an adorable new pet rat, she s only two months and very timid. I m trying to help her become comfortable with her new home and I ve heard reading and singing to your pet rats helps them become used to your voice and feel safe. So I m looking for a nice song to help coax her out of her hiding and ease her into a comfortable state of mind.