From The Wall Street Journal...
A researcher, John Sloboda, more than 20 years ago figured out how the specific arrangements of notes in a song, paired with vocal melodies and harmonies between vocal and musical layers, actually creates a physical emotional reaction in a listener. Translation: You can literally play specific notes in a specific order in order to make someone cry. These notes, or their order, are called appoggiatura.
A note that augments a pleasing sound creates enough dissonant sounds (think anything but a perfect 4th or 5th--yes! Music Theory geek!) that it causes a small, subconscious level of distress in a listener. Rescue them with a pleasing crescendo or chorus, reiterate it, and then layer it with staggered timings (basically the same structure of any pop song), and you have successfully played an order of notes that can physically cause tears.