1- We had a man singing to us as we sat in the restaurant having our meal.
2- We had a strange woman come to the door selling pictures.
3- I just had them doing stretch routines, and after, they got really good at it.
4- A: Is there running water? B: Of course, there is running water. B: Oh, but I wouldn't use it. It is very contaminated. We had three dogs die in the well.
5- I have half the Committee coming tonight.
What is the difference between "have someone do" and "have someone doing" ?