It is illogical to say that "electricity" or current or voltage is an electromagnetic wave.
This all means the electromagnetic waves must be traveling through the copper, not outside the copper.
First they aren’t and then they are? To deny that audio signals are EM waves is to deny basic physics. I suggest you go take a basic physics class about these topics as your analysis is I’m sorry to say.. fundamentally flawed. Take a look at this chart
https://en.wikipedia.org/wiki/Electromagnetic_spectrumUsing the common ways of describing it in terms of voltage and current always breaks down at some point, like the water through a hose analogy. It’s OK for grade school to start to get a grasp but it oversimplifies in ways that can’t be supported and at some point (we are there) just causes confusion.
Trying to differentiate some portions of the spectrum by saying that some are made of photons is basically incorrect. There are two common ways to analyze light and all other EM waves. Photons, which treats it as particles and the EM wave which of course, treats it like a wave. For some phenomena particles works better, for some waves work better. To try and differentiate between the 2 to explain an ill-conceived position just muddies the waters. Since to get the clearest picture you need to use quantum physics which is clearly beyond the capabilities of most here including me, we simply must trust those physicists who do understand it.. like Einstein.
It is not incorrect to use photons to discuss EM waves at audio frequencies, it just generally serves no useful purpose.
Once again and I will drop it, but to claim that all of the energy is contained inside the wire falls apart with simple experimentation. Electromagnets would not exist, electric motors would not work, and on and on like I pointed out above. To deny this is again denying basic physics. I guess the earth is flat too since you can’t see the curvature from where you are standing?
BTW, you may or may not have noticed that I haven’t posted much for several years and this thread is a perfect example of why. A perfectly logical question is asked (cable direction in case you forgot) and somebody (usually the same guy) jumps in with pseudo-science and voodoo to try to explain a position that is fundamentally flawed and flies in the face of all known physics. Said person will then endlessly defend their defenseless position until we end up where we are today. My apologies to the OP but sometimes you see something that is just so blatantly wrong you have to speak up.