Yes they should otherwise what's the point in watching them, and I think the same about TV performances. If they want to dance around without actually singing then that's fine, they can become a dancer. If they want to be a singer then they can bloody sing
And if they want to create an illusion of singing and dancing at the same time then that's what music videos are for.
It has to be the only job in the world where you can become a millionaire for NOT doing your job. Pisses me right off
