It's a flycatcher. Which one I don't know but probably a least flycatcher. I just appreciate the fact that it is eating the insects flying around my perennial garden.
It is very neat to observe because its head is constantly moving & watching for that delicate insect morsel that it will fly off to catch in mid air and then return to this perch to watch for another.
One of the many birds I enjoy spying upon in my yard.