You expect your grandchildren to reveal their musical tastes to you?
If my grandfather asked me if I knew who The Rolling Stones were I’d give him the old blank stare and I’d be concerned he was conspiring with my parents to confiscate my clandestine record collection.
I do see your point.
And with the fact that they now listen to music with litty-bitty thinga-ma-jigs stuck in their ears all the time, I have no real idea of what they do listen to.
In my day, it was wide open...cranking those Bose 900's to one point below max, driven through a Kenwood Amp, with a Marantz Direct-Drive 6300 turntable, upon which turned a piece of vinyl plastic with little squiggly lines upon it which translated out to Iron Butterfly enthusiastically banging out In-a-gada-da-vida, baby!...damn sure meant I couldn't hide my taste in music.
In fact, people in the next county knew what my music was.
My 20y y/o son (a Trump fan who is studying music production & business) thought Sia had a good voice and costuming but said the dancer was “offputting”. He also thought that including Trump in the “Drake dancing” skit was an example of crossover marketing to youth that conservative candidates should do more of.