Project 365 day 175: mystery shrub

This large white flowered shrub blooms very profusely but quite briefly around midsummer, and seems happy in its rather shady corner close to the house. It was planted by the previous owners and I've not identified it through Google search; I'm embarrassed that it's only in our eighth summer admiring it that Blip has made me curious enough to try to find out what it is. The extra shows the blooms fully open; if you know, please enlighten me. 

I'm again posting a day late, as I've done several times recently. I often struggle to download, process, select and post photos in the late evening slot when I usually need to do it, spending too long dithering about which I like best and running out of time to share them. Last night, though, J and I decided it was time for a movie night, and spent much of the evening watching Nomadland, thanks to her Disney Plus subscription. I liked it very much - a quiet, slow, reflective film with some beautiful cinematography celebrating the empty landscapes and vast skies of the desert states.