Answer
The answer is "Runaway", Aurora's breakout hit released in 2015. Initially gaining traction through word-of-mouth and online platforms, "Runaway" surprised the music industry by gradually accumulating massive popularity and becoming a sleeper hit. Its combination of ethereal vocals, experimental production, and introspective lyrics resonated with a growing audience, turning it into an enduring success for Aurora and establishing her unique artistry on the global music scene.