This past Saturday at the Coachella music festival, Justin Bieber played the first of two headlining sets in a deal reportedly worth $10 million. It was his most significant solo performance in years. But Bieber spent some of his time on stage the way many of us do on Saturday nights: on YouTube. For some of the set, Bieber played parts of his older songs right off YouTube from a Mac laptop. Behind him, on the stage's screen, you could see YouTube's website as he searched for songs in real time and then put the videos on full-screen while he sang along on stage.
"I'm sorry to cut it, but these are little snippets. I just want to see how fa …