While neighborhood bees are unlikely to agree, I think that the pink calyces of the Seven Son tree (Heptacodium miconioides ‘Temple of Bloom’, below) are its primary attraction and not the small white flowers that faded a few weeks earlier. Of course, a bee’s concern is nectar, not blooms, and without question I prefer lovely blooms to slurping nectar.
Fortunately, the Seven Son tree fills the bee’s need and mine, and why this small tree is not more common is a mystery. Someone has dubbed the Seven Son the northern crape myrtle, I suppose for its multi trunk form and summer flowering, and while its flowers do not match the showiness of crape myrtle, the extended period of color is exceptional.
I was distressed when a large Seven Son snapped at the ground in a summer storm several years ago. I figured it would quickly grow back from the roots, but it didn’t, and since that time I searched for a sizable replacement without luck until a year ago. The spot where the Seven Son had grown has long been filled, but when a bushy, four foot tall tree became available I found a spot for it in a hurry.
It will take a few years for this young tree to get to a substantial size, but already I’ve welcomed back its color in late summer and early autumn.
Ramblin' through Dave's Garden 
I also have one of these trees in my yard here in southern NH, and I, too, am surprised that more people haven’t planted them. Indeed, I’ve never seen another one in this area. Their peeling bark is also attractive, but some rodents keep stripping it off, probably for nesting material. And when in bloom in early Sep here, the bees go nuts over access to its flowers.