White

I think that this a variation of mock orange. It certainly has a gorgeous smell of orange!

The flowers grow in ball formations. I have had it in my garden for many years, but have never known what it is called.

I have searched on Google but can't find out what it is - anyone know?

EDIT - KirstenR has suggested that this is Viburnum opulus "Roseum" known as the snowball bush, and I think she is correct! Thanks Kirsten!