Compare with Philadelphus inodorus.

Thank you both! I assumed it couldn't be Mock Orange since it didn't have a scent, but now it makes sense. Thanks again.

Wow, scentless mock-orange...and it’s native to the eastern U.S.. That’s new to me. The interesting thing is the flowers are actually fragrant. Wait, what?

I love my 'heirloom' mock orange (I don't know the name b/c it was here when we bought the house 20 years ago). No scent (I'm in a Boston suburb), but otherwise a glorious shrub. Mine is 12' high x 8' wide. Was planted decades ago, and has never failed me in 20 years - even when I had to cut alot off it mid-summer due to poison ivy wrapped around it bloomed the next spring (June for me) and always has alot of healthy green stems (canes?). Provides privacy screen from neighbors' driveway and the street.

the flowers are actually fragrant

Philadelphus at any rate, whatever the species (there are about 80 plus all the garden forms). I suggested P. inodorus because as I remember it in the past other posters on this site have said ones being called "dogwood" in the South were examples of this species.