P eer closely at the cover of Born to Run – Eric Meola ’s enduring, black-and-white portrait of Bruce Springsteen as he leans against his bandmate, sax player Clarence Clemons – and you’ll notice a button clipped to the singer’s Fender Telecaster guitar strap. Small and easily missed amid all that leather, it reads: “Elvis the King, King’s Court, Elvis Presley Fan Club of NYC.” It’s no great secret that from a young age the Boss had worshipped the King. So on the night of 29 April 1976, 50 years ago today, the then 26-year-old decided to demonstrate exactly how much. It was 3am. Springsteen had just played a show in Memphis – another stop on his Born to Run tour, the eight-month crusade that had turned a scrawny, scrappy bar-room poet from New Jersey into a cover star on both Time and Newsweek . Fizzing with post-gig adrenaline, he hailed a taxi and asked to be taken to an all-night diner.…