There were no shortage of Prince tributes this weekend — especially with Coachella barreling into its second weekend and all — but few matched up to the passion and prominence of this one: Bruce Springsteen, one of the last of Prince's reigning '80s superstar contemporaries, opening his Saturday night concert at the Barclays Center in Brooklyn with a stirring rendition of "Purple Rain" — on a purple-drenched stage. Sing it, Boss.