My own Son is 4+1/5, and our treat at night is for Dad to sing him some songs, this has being only going on now a few months.

His favourite I'm afraid to say is 'Whiskey in the Jar' - I'm already corrupting him.

All in all he has his repertoire of about 6 songs that he sings the words to me.

Two little boys
Spanish Lady
Rattling Bog - a particular fav. of his is this one
Dublin's fair city
Whiskey in the Jar - His constant request
Puff the magic dragon

I know they might not exactly be lullabies - but he gets great fun from them.Yet when signing them during the day - our 18 mth old daughter always stops what she's doing to listen...maybe they are OK ??
Beyond that Dad's own repertoire is exceptionally limited anyway !
But 'Summertime' 'Silent night' or 'The little drummer boy' make their occassional sounds...

Rgds

Diesel