Kellxx - I'm a Beatles fan too - I think my parents got me in young like I'm doing to Lucas. I mostly sing Obla Dee Obla Dah & Elanor Rigby (hope I'm not scarring him with that "all the lonley people") 'cause I know all the words. I love Beautiful Boy - DH did a video when Lucas was 3 days with that song and it always makes me cry.

I also sing to the tune of the Mickey Mouse song:
Who's the baby we all love
We love so very much
L U C Aa S
Lucas Michael B....

And my own invention (such as it is)
Lucas, Lucas he's my favorite boy
Lucas, Lucas he is such a joy
Lucas, Lucas he's my favorite thing
Lucas, Lucas he just makes me sing.