"Ultimately it increases entropy... let me tell you about the heat death of the universe..."

"No, Mom! I'm still afraid of the False Vacuum monster laying underneath my ground state!"

Heat. Everything ends up as heat.

Where does the light go when you flip the switch?

Check your fridge.

it goes into your soul

It goes into your memory. That's why you can remember a song that you heard before.

In your ears

the music goes back again to be later re streamed to other people that might need it

It goes out into the world, to be merged alongside all of the other sounds, until it can be recycled as "new" music and you can enjoy it again:-).

"Everywhere, all at once. That's why if you put your ear close to speakers it might collect too much and that can hurt your ear"

The music stays in your head until your forget it. Music only exists in your head

we hang it on a wall of silence in the room of our imagination

It's still there, it's just in the past now.

"And can you please tell me, oh

Where do broken hearts go?
Can they find their way home
Back to the open arms
Of a love that's waiting there?
And if somebody loves you
Won't they always love you?"

Really reminded me of this - the incorrect, useless, but poetic answer could be that it's just like with love. Into the open arms of the music thats waiting there.

Tell the truth in simple. I was annoyed to learn that there aren't any crawlies that go back up your throath if you swallow toothpaste.