[anigbrowl]

Um, no. You have to publish or perform it publicly to be infringing. If you sign it at home, or record yourself singing it at home, or record a copy of the original at home, you're still not infringing as long as you don't attempt to distribute it.

Unless your shower is located on a stage and you charge admission for people to listen to you sing in the shower, but I'm pretty sure that's not what you meant.