My son sings. All the time. All. The. Time!
He sings at the park. He sings while he's eating. He sings when he's on the toilet. That's just how he rolls.
He loves to sing. He really loves to sing! (Maybe we've been spending too much time singing karaoke, and now it's rubbing off on him?)
He isn't a very good singer, but he's better than most. He can carry a tune, and you definitely know what song he's singing.
And when he has a song in his head, he sings it. All the time.
Currently, he's stuck on Avril Lavigne's song I'm With You. He sings it night and day.
I usually join him for the chorus.