To my knowledge I have heard 1 (one) song of Taylor Swift.
I to my knowledge have never heard a coldplay song.
Could I have heard them with out knowing and/or in the background or driving listening to the radio? Well yes of course.
There is a difference.
Haven heard it and knowing it and maybe have heard it on the radio some time during your life time.
Also I find it plausible that a black dude that focus on jazz never really listen to Nirvana
Also what about Moffet?
I posted his video in here.
Dude claims to never have heard Numb by Linkin Park.