It is funny how some songs come into your life fully formed, straight out of the gate announcing: “Here I am, love me!” And for the most part, you do. Some take a scenic route, passing you by, tickling your funny bone until you finally stop and take notice. Others float in passing, never to be heard of again, and the pestering ones batter you to submission until you just have to give in to Rhianna and pon de replay. And then we have the shapeshifters. “Heartbeats” started life as a dark and twisted tale of razor blades and drunken romance on Swedish electro band Knife’s sophomore album “Deep Cuts.” Another Swede, folk troubadour Jose Gonzalez made a quiet and contemplative version, full of introspective ruminations on love. Nine years after the original release, Ellie Goulding has made an acoustic version which is much lighter and sweeter. It dances like heavy raindrops that break a heat wave, or like a butterfly fluttering in the setting sun. Simply sublime.