For budget reasons we need to keep the RD small. We are inviting only the wedding party and their spouse, people involved in helping with the wedding ceremony itself, and the officiant. FI's grandfather is a musician and is traveling from many states away to sing a song he wrote for us. He and his grandmother will be invited but do I have to invite our other grandparents? I don't think they'd even know he was invited and they weren't. I think he goes along with the WP since he's actually involved in the ceremony but my mom thinks I need to invite all the grandparents. We are paying for our rehearsal dinner ourselves.