Sound is just the vibrations of the air, so as music fades, the air calms. Echoes, reverberance, they are just a result of sound "dampening", and as each sound wave hits a surface that it reflects from the sound waves are also dampened.

So is the question where does music go? Or is it really, "where does silence come from?"

syncs brain cells for later

As someone with a degree in Philosophy, I don't think this is really a philosophical question. The science is interesting and useful to know

My guess is the music goes into the past, leaving echos in your memories.

Category error.

If we can try with every day
To make it better as it goes
With any luck then I suppose
The music never ends

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.

It goes into the ears.

"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.

It goes straight up my ass!

that happened