...but unfortunately, Amazon has set up restrictions:
"Response length – The combined total time for the entire audio response generated from the components cannot be more than 240 seconds."
BUT...
"Our API throttling limits will allow up to 30 calls within a 60 second window…anything above that will block subsequent requests for the next 15 minutes."
So, no creating a music box isn't really doable - a text reader/TTS no problem!