The conversation began with your assumption regarding the average yeshiva bachur — which I strongly maintain is completely incorrect. The average yeshiva bachur, aside from as you acknowledge does not listen to goyishe music, also generally does not know the goyishe musicians and songs. Despite any contact he has with his “not-so-yeshivishe friends” (as you put it.)
Regarding my second point, that is certainly the impression I’ve gotten. You seem at least somewhat dismissive of more contemporary meforshim when you feel you cannot find sources earlier than some artificial time limit (i.e. over 200 years old – but that is just an arbitrary example, I don’t know what your limit is) agreeing with “contemporary” meforshim and/or Daas Torah.