Nope I don't sing to my cat however I do use a higher tone to my voice which always gets her attention. If I'm caught singing it's because my cat walks in on me getting ready for work or something. I must have a decent voice because she'll walk in and stare and sit by me as if it's soothing to her.

singing to your cat
 

My wife sings to our older cat, Tabitha. The cat usually responds by changing whatever she is doing at the time. If Tabitha is laying down, the singing will make her get up and walk somewhere. If Tabitha is hiding, the singing will get her to come out.

Aww, no, I don't sing to my cats. Even when I'm singing around the house, they don't seem to care.

The dog, however, will flip out if you sing certain songs. He doesn't like pitch issues, lol.