Throughout human civilization, dance has been considered to be a means of communication. With advances in Artificial Intelligence (AI) and Robot Technology (RT), it is now possible to create biped humanoid robots that can dance. This manuscript provides an overview of dancing robots that have been developed during the past 24 years. It then introduces several emotional flexible spine humanoid robots developed by the author. As part of the introduction, it presents the world's first humanoid robot that can exhibit dynamic walk with flexible spine motions. This is followed by a discussion on applications, some development issues and possible future directions of research related to dancing robots.