Timing key to music’s emotional hold

MCGILL (CAN) — How one piano performance makes the listener swell with feeling, while another makes him look around for the nearest exit, all comes down to the physics of the instrument.

“All of the subtlety and expressive nuance in a performance—the parts of it that make you feel joy, sadness, or hope—can be reduced to just three factors: how long the pianist holds the notes, how loudly he or she plays them, and the pedal positions,” says Anjali Bhatara, doctoral student at McGill University. “This is information that we can then actually measure and manipulate.”

By using a Disklavier, a specially modified piano keyboard containing hundreds of sensors and miniature motors beneath the piano keys, researchers used a computer to register the precise and nuanced movements made by a concert pianist while performing one of Chopin’s Nocturnes.

They then worked on the computer files to create a number of different versions of the performance. The timing, loudness, and pedaling were manipulated to create a continuum of versions of the piece, ranging from 100 percent expressive (the original performance) to 0 percent expressive—a wooden, robotic version in which every note is played at exactly the same volume and for exactly the same length of time.

Study participants listened to the different versions that were played back to them in random order, without any indication as to the degree of expressivity in the performance, and were asked to rate on a scale of 1 to 10 how expressive they found each version.

Even non-musicians both recognized and preferred the more expressive versions of the music.

The research is published in the Journal of Experimental Psychology.

“They might hear an 80 percent followed by a 20 percent followed by a 60 percent expressive and they were consistently able to recognize and choose the more expressive version, says Daniel Levitin, professor of psychology.

“This tells us that even very subtle differences in performance are readily identified, even by average listeners. I found that astonishing.”

Variations in timing have an even greater emotional impact than do variations in the loudness of playing.

“The skilled pianist has learned to communicate musical emotion primarily by making some notes longer and some shorter, some louder and some softer, just like we do in normal conversation,” Levitin says.

“It stands to reason that one might be more important than the other, but I was surprised when it turned out that timing is more effective than the loudness in making you feel something.

“One of the hopes of this kind of research is that it will help us to better understand the alchemy of what goes into a moving performance,” Levitin says.

“It’s really a big step forward in capturing and quantifying why music is emotionally moving.”

The research was funded by the Natural Sciences and Engineering and Research Council of Canada and the Social Sciences and Humanities Research Council of Canada.

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