Just a thought, could yours be a white fringe tree, Chionathus virginicus? This is a deciduous tree, the flowers are also white and hang downwards. We have one big white fringe tree in our park, when it flowers the whole tree is covered with white flowers. Very majestic.I tried to change my post...it was supposed to say NOT evergreen.
Rats, have kept them going for years waiting for them to start to bloom. When I got them I looked them up and it showed a tree covered with white blooms. The book said the small white flowers hang below the leaves -showy etc.
Rose