I bet you’ll find you don’t need to know the original material to find him funny. He’s not merely satirizing songs; he’s largely using their melodies and arrangements as a medium for his own funny lyrics; he also creates several of his own melodies.
No, he’s very talented and sharp. But it just doesn’t have the same kick when current pop stuff hasn’t been inflicted upon you at all. I also like his originals and the medleys, but his main gig is making fun of the newest thing at the time, and it doesn’t work as well if you thankfully haven’t been subjected to the newest thing for years.
He should do a classics album or go back and get some of the songs he missed, but then of course he’s cutting down on his audience in the other direction.
FReegards