Hey How are you doing?
I say singing the words to a song especially a song that is so anointed on it's own will not only help with expression, but it will help as far as your dancing overall. How is that? Well try looking in the mirror and not singing the song and then try it singing the song or even just mouthing the words. There is a difference. Believe it or not but when you singg an anointed song from God while you are dancing and you are speaking those words over the people it breaks strongholds, it tears walls, and it will set another atmosphere. It causes people who couldn't get the message through your dancing get it from you singing to yourself or mouthing the words.
But to me you can't be singing any kind of song just like you can't be dancing to any kind of song. You don't want to put more on the people then what they already carrying nor you don't want to place the wrong thing in their spirit. That's why I am saying the song has to be anointed itself and you know the whole you can't sing and dance to any kind of song.
I hope this help out a little.