Contacting my Cast about their part in my Music Video

I have now contacted all my cast and asking them if they wanted to be part of my music video and the production of it. I am hoping that they would all be happy and excited to be in my music video so it would make it easier for me to film them as they would be enjoying themselves and making my video more fun and relaxing. However, if they say no, I would need to re-cast and think of other people who would be ideal to play the characters in my music video and be comfortable to feature in the video.