Earlier quoted context omitted.
When I wrote radio - I meant generally 'something with a speaker' because irrespective of what 'radio stations' do - playing music on 'something with a speaker' from CD, iTunes, MP3s etc. on your lawn, in your car, on the beach, while at work - is extremely common - and does not constitute a 'public performance'. You're basically implying that 'everyone is breaking copyright all the time' which is a spectacular claim…
I think you’re confused. I have said elsewhere in this discussion that public performance excludes performance only to a small group of friends or family.
Millions of people play unlicensed music beyond the narrow interpretation of this statute every day, and there's 200 years of case law that I referred you to that doesn't come anywhere even close to indicating that any court is going to take a narrow view of that statute.
The case law highlights where that 'boundary' is and it's beyond a cop or anyone else playing music from their person, on the job or otherwise.