I love to sing in the shower. I sing all day long. It drives my DH crazy!
My favorite bathtub song is one from John Prine's That's the Way that the World Goes Round. One chorus goes like this.
I was sitting in the bathtub counting my toes,
When the radiator broke, the water all froze.
I got stuck in the ice without any clothes,
Naked as the eyes of a clown.
I was crying ice cubes hoping I'd croak,
When the sun came through the window, the ice all broke.
I stood up and laughed and thought it was a joke
That's the way that the world goes 'round.
A great bathtub song that always makes me smile.