First of all, regarding LA CAGE, it was difficult to do this number in context out of context. When Grammer introduced the scene, the words didn't hit. And the ending of taking off the wig therefore made no sense.
Secondly, it didn't help at all that the camera angles worked against them. The camera shots didn't exactly capture it best (as best as a live experience can be captured on film).
"The Spectacle has, indeed, an emotional attraction of its own, but, of all the parts, it is the least artistic, and connected least with the art of poetry. For the power of Tragedy, we may be sure, is felt even apart from representation and actors. Besides, the production of spectacular effects depends more on the art of the stage machinist than on that of the poet."
--Aristotle