Very interesting to see the parts of Cambrian I'll never be able to reach.
As for music, yes, it's a very emotive and personal thing. I would prefer to hear the natural sounds of the underground world: - the clanking of slate etc, the sound of distant water...or in this case just bubbles (however horrid!), as a soundtrack. But maybe that's just me.
I currently watch most videos on Utube with the sound off 😉 🙂
'I wonder how many breakfasts, and other meals we have missed inside that nasty clockless, timeless hole?'
'The Hobbit'
J R R Tolkien.