I studied my sister as she listened to some music on a CD player. She had borrowed my dad’s humongous pair of headphones, made to disable any surrounding sounds, other than the music itself. It was immediately apparent to me that she enjoyed the music, because she swayed her head back and forth, sometimes gently and sometimes vigorously. She tried her best to sing every single word, off key or not. She continued, until she laid down her head, and fell into a deep sleep.