A little embarrassing to admit this, but I find it harder to listen to a new song or genre if that's the main activity I'm doing - like sitting down to just focus on the song. If I put it on while washing the dishes or driving I don't feel as pressured about it.

Maybe this is involved a bit? asking your son to listen to something could be making it an activity, maybe put it on while you do something else and then ask his thoughts on it after?