Tone-deaf? You can learn to sing!
Certain artists are born with stronger muscles and so achieving musical strength is easier and faster. While we may never attain the greatness of naturals like Aretha Franklin, Freddie Mercury, or Michael Jackson the good news is that with a bit of practice, those of us who are less naturally gifted (or branded "tone-deaf") can bulk up our singing muscles too.
Just like a muscle, your voice (made up of lots of muscles) can be trained, strengthened and rendered better.