Sometimes you just want to listen to a bunch of nostalgic 2000s hits, and other times you want to revel in the beauty of Harry Styles's masterpiece Fine Line for the 50th time. In either case, ...

First there’s Pitbull. “I know you want,” he chants. And then: “Pop,” “dance,” “rock ‘n’ roll” — the genres burst out as the video cuts to Lady Gaga, Kelly Clarkson, will.i.am of the Black Eyed Peas, ...