If you have a couple pictures - close up and far away - and you post it to the "name that plant" forum here, you will typically get a quick answer from experts.

Here are some pics...

It sure does look like a crabapple to me, I think you're right. Some varieties do grow tall and straight, especially the weedy ones. It's usually the ornamental dwarf cultivars that people grow on purpose.

Yes, that's a crabapple. It will have grown skinny if it was surrounded by other trees and bushes.

It might not even be a variety, it might have been a seed volunteer dropped by a bird. Is there a graft line?
Carla in Sac

Oh I am confident it is a seed dropped by a bird. It was among a thicket of buckthorn, mulberry, wild cherry, grape vines, etc. I cleared all that nasty stuff but spared this one tree because of its beautiful flowers. But you are right, it is there accidentally and there is no graft line.

I guess I just thought that even trees dropped by birds could be roughly identified to a specific variety.