I knew what music my parents liked, because they listened to it on a big ol' record player that was always playing in our living room.

My first child was gen X. I knew most of his music, because he played it on CD and I heard it playing in his room and car. When I go to his house, he still plays it through a variety of devices that broadcast it through the airwaves in the room so every body can hear it. ("Alexa.. play Smashing Pumpkins...")

My second child is a millennial and I never hear what she listens to because she listens with ear buds. So now the circle of inter generational music recognition is broken.