Okay, I have two things to say about this clip,
but you should watch it first.
First, I saw this with some 18-year-old kid who's only point of reference was the Will Ferrell movie ELF. Honestly. A sixty year old song and his only connection is ELF.
Second, I'm pretty sure that in this song Darren Criss proves he's got the best voice of anybody on that show. Others may be louder or bolder or more dramatic, but I haven't heard anyone bend and inflect notes with the skill this boy has.