Using CoRE, I used the same virtual switch as the previous solution. However, now the switch is a trigger for a CoRE piston. When the switch is on, then “Using Living Room Speaker, Play”; when it is off, :“Using Living Room Speaker, Pause”.
I ended up going a different route than CoRE. I installed the AskAlexa app, and using that, I managed to gain additional controls that a simple switch couldn’t provide. In its natural state, Alexa can only control lights and switches. Using AskAlexa you gain the controls for the device based on its type (Speaker, Light, etc).
With AskAlexa, I can now Play, Pause, Skip. It supposedly also supports volume (and in fact, it responds saying it set the volume), but the volume doesn’t change. I’m not sure why that is, and I hope to ask the Ask Alexa folks if they have a solution to the problem. It takes a bit more effort to install and get AskAlexa working, but the instructions are pretty thorough, so if you are technologically adept, I recommend it.