It was long a source of embarrassment to me that I could easily be moved to tears by music. Suspecting that I was slightly autistic helped a little - not to mention explaining my memory for trivia! - but still, a fellow doesn't like to tear up at the end of a bad movie just because the orchestra wells up.
It's not just me, though. I've met lots of other people who have the same reaction, even if it's just a 30-second television commercial. How can music produce this effect so quickly, even when the extramusical situation hardly calls for it?
A British researcher named John Sloboda asked subjects to name several songs they regard as really sad, compiled a list of 20 really sad songs, and then studied them for measurable features. He found that nine out of ten of sad songs contain appoggiaturas.
An appoggiatura, from the Italian word for leaning on something or someone, is when a singer or musician glides into a note from just above or just under it. The grace note that slides into the "real" note is usually dissonant when sounded against whatever harmony is going on.
An example is Adele's "Someone Like You," which has an appoggiatura on "you." This is a good example because Adele's songs can be such tearjerkers that one of the late night hosts joked that she was so happy about her Grammies, she now has nothing to sing about.
Sloboda has more work to do, though. He can start asking himself why Frank Sinatra so often entered a note from a higher grace note without creating any more impression than that of masculine emphasis, and after that he can ask himself why Billie Holliday, doing the same thing, sounded so poignant.
Musicians have known for centuries that dissonances create tension, with their resolution creating relief. Aaron Copland scored lush romantic music for a movie scene in which a woman waited for the arrival of her lover. Each time she rushed to the window hearing hooves, the music was hopeful, then stopped being hopeful when the horse kept going. In trials in a theater, the audience laughed. Copland rescored the music with lots of dissonance. Then the audience felt the young woman's pain.
This doesn't mean it's always better to load music up with ornamentation. The most striking thing about Whitney Houston's singing was its purity. She had a church choir upbringing but employed with great restraint the gospel ornaments that are so overused by many lesser singers who use and abuse ornaments because they think it makes them soulful.
I always thought the Fifth Dimension ("Up Up and Away") sounded better before they got voice lessons, and maybe that was because their sometimes out-of-phase vibrato created emotional tension in their early hits.
Handel thought his singers overdid the ornaments and allegedly hung a woman upside-down out a window until she promised to sing only the notes he wrote.
I wish to close with the heretical assertion that the ""Ode to Joy" in the finale of Beethoven's Ninth is routinely ruined by excessive operatic vibrato that blurs his excellent harmony.