So apparently I'm the last to know, but this guy Sam Tsui is a 23-year-old musical genius who happens to be totally adorable. He applies his talents to a slough of pop covers on YouTube (in spite of having a degree in classical Greek from Yale, no biggie), the latest of which gave me the urge to bow down to his superior awesomeness. Mind you, I'm not even a fan of Britney Spears — I know, I'm sorry — but this mashup of... all things Britney makes me want to give all her albums another shot. Take a look at this truly epic video after the cut. 

Sam is also the backstage host of The Sing-Off, but I think Disney needs to just come write him a check already. [source]

In this case, Sam has a question for you:

Had an absolute blast mashing together some of the Princess of Pop's biggest hits - see if you can recognize all fourteen songs I used!

Can you name them all?