Thank you
Sauce for reminding us of the fairly successful adaptation of
Pullman's
His Dark Materials.
I would think that it is less a matter of converting the dialogue to song and the action to dance as to translate the many extensive passages of description of Middle earth into the set design and stage scenery. The theatre for this production, The Princess of Wales theatre (yes, it was named for the late Diana, Princess of Wales) will be renovated so that the stage will have 16 elevators.
Perhaps more intriguing for audiences will be the renovation of the audience area into a Middle-earth forest. Obviously the backers of this production realise how much many readers of Tolkien long to live in Middle-earth.
But don't let me stop the jokes. Here's a link for
The Lord of the Rings Musical to inspire you all. Some might be impressed with the opening intro and music.