I would like to know what this blossom is. (It is serviceberry, thank you Jenny W for the answer!)

La Sierra de La Cabrera.
This is everywhere. I know that in late June, early July it produces fruit that looks and tastes exactly like blueberries, blaeberries, billberies (and myrtle, whortleberries too?).
The berries confuse me. I don't know which are the same but just called different names in different places and which are from another family. The point is I've never seen blueberries growing on a tree before, only growing at ground level! Can someone enlighten me?
Jenny W has found the answer and I give a wiki link here: en.wikipedia.org/wiki/Amelanchier
Thank you, jenny!