For some reason, I started singing "Jug of Punch" as sung by the Clancy Brothers and Tommy Makem to my son, and he loves it. It's a nice little ditty and the repetitious chorus ("Tora lora low, Tora lora lay") really calms and comforts him.

Of course, I've also re-written several songs and put his name (Duncan) into them. It's fun to play around with that stuff.

I'd guess that you will probably just start singing something to him and he'll just take to it - there's something about hearing your papa sing that makes a kid happy. I loved hearing my dad sing, and he couldn't carry a tune in a supertanker.