I like the premise. Last month's Douglas Hofstadter quote comes to mind. Some problems:

At some point, a young person asks you how some simple loops of electrical signals can engender music and conversations... you insist that your science is about to crack that problem at any moment.

Why would I insist this? I don't even know how the electrical signals (the what?!) change the volume. I just know how to make the wires change the volume, and I know how to make them change the music too.

You would conclude that somehow the right configuration of wires engenders classical music and intelligent conversation. You would not realize that you’re missing an enormous piece of the puzzle.

Some inquisitive Bushman I turned out to be. This is still a very magical radio.

Also, I think a clever Bushman could figure out that the radio is transmitting sounds from somewhere else. It is the reality after all so there are clues. He hears a person talking when no one's there; the circuitry is too simple to write symphonies and simulate most human discussion; the radio doesn't work in caves...