That's interesting, I've only heard "syringa" in reference to lilacs. Meanwhile that lovely shrub with the white flowers sounds a lot like philadelphus coronarius, which my grandmother called 'mock orange'. We had one in the back yard at the entrance to the vegetable garden - I imagine it's still there unless they've finally torn the place down. It blooms about this time every year and fills the yard with a sweet orange scent that's always pleasant and never too powerful.
All the best from BC.... it's heating up here now! Whew!