Whoelheartedly recommend any of the above options, but there's other factors.

If you're dealing with the right, supportive group of people, chances are that singing any song, regardless of quality level of the voice singing it, will be appreciated - as long as the spirit behind it comes through.

At a shanty sing one night, a young lady stood up and sang "Home Dearie Home" - couldn't stay in key, off tempo, voice cracking and all. Yet something about the look on her face... the emotion in her voice...

By the end, several people were in or near tears (and not due to the voice), and she was roundly applauded.

It was somehow both one of the worst, and most beautiful, renditions I'd heard.

SeanM