It's already confirmed that Eddie will be singing.
They played the intro to "All That Jazz" when CHICAGO performed "I Move On." It's fine if it's intro music. They don't need to be too cautious.
"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