To Miyabi Matsuoka, the harp is a mirror that reveals who you really are. She says she can tell the personality of a harp player by the way he or she manipulates the instrument, which affects the sound they create.

That's why she asks every new student at her private school in Tokyo's Mejiro district to play the popular lullaby "Twinkle, Twinkle, Little Star" during their first lesson.

"The harp is a simple instrument in that you touch the strings directly with your fingers," the demure 39-year-old says. "That means your state of mind and your personality traits are more directly reflected in your sound than in other stringed instruments. I can tell whether the players are impatient, tough-minded or faint-hearted."