I would love to see a closer image of a leaf to help positively ID this. If you can post another photo, please do.
It is definitely not privet.
Although the bloom is close to a Fothergilla, it is quite different, and the leaves do not appear the same as a Fothergilla.
The bloom looks very close to a Fringetree/Grancy Grey Beard/Chionanthus, but the leaves I see in the photo do not match up to my knowledge of a Chionanthus (both Chionanthus virginicus and Chionanthus retusus).
I am not familiar with the Western White Clematis, but the leaves that are visible in the photo do seem closer to images of that Clematis. I am still not sure about it though.
A close up photo of the leaf would help me a great deal.