CR 7 on Instagram: "Whistle notes sit at the very top of the human vocal range, reaching frequencies so high they overlap with the sounds dolphins use to communicate. That’s why this reaction is so striking—when Mariah Carey hit her iconic whistle note, the dolphin wasn’t just entertained, it was responding to a sound that lives in its own world. A rare and beautiful moment where music and nature meet in harmony. It also shows how powerful her voice really is. Mariah Carey has always been known