Music video shoot - BIG person on stage

I am not sure if this is the right forum to post this, but since i am using after effects for the goal, i thought of putting it here.

We are working on a music video, where the singer/rapper needs to look BIG on stage. By big i mean, he needs to be twice or 3 times bigger then the musicians behind him.

We already worked out the medium/close shots, by using simple camera techniques.

But we need to have at least one long wide shot where the singer is big on stage and the musicians normal size at the back.

The easiest way would be shooting the stage with only the musicians and the talent on green screen in the studio.
Because it is a concert(not live) the lights will have different light colors and possible will move around(need to check that)

My second thought was putting the chroma key on the stage, but the dark and the different light colors will make it hard or impossible to key(?).

Any suggestions what could be the best option??? Anyone had something similar(hard chromakeying).

T

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