Get someone from the Netherlands to sing you the traditional Dutch birthday song. It's a gas, and would lend itself very well to the sort of harmony singing you get in the traditional clubs or the Christmas carol sings in Yorkshire.

I don't have a copy of it to post because I only heard it live, sung to Packie by a wonderful lady from Holland who lives in the area. (This was at a private party for his 88th, not the recent big bash.)

All the best (and happy birthday) -

Bonnie