Why is happy music bouncy and sad music heavy?
If you read the lyrics to "Close to Me" by The Cure, you'd be forgiven for thinking it would put you in a melancholy mood.
"I've waited hours for this.
I've made myself so sick.
I wish I'd stayed asleep today…"
But give the song a listen.
The tinkling ivories and snappy beat are just plain happy. Music, beyond lyrics, sets a tone. It can be up tempo and light or slow and plodding and these qualities telegraph emotion the same way that a person walking can look happy or sad depending on their gait (bouncy step vs downcast trudge).
Because of this similarity of expression, we wanted to test whether music and movement shared the same dynamic structure consistent with music and movement using the same neural hardware. We tested this idea by creating a computer program that uses the same dynamic features to create either music or movement.
Beau Sievers wrote a program that presents a user with five slider bars. Each slider bar corresponds to one of five dynamic features: Rate, Regularity of rate, Direction (up/down), Size (big/small), and Smoothness. The sliders operate in real time. By manipulating the slider bars, a person can alter the music notes being played or the animation being shown. For example, manipulating the RATE slider makes the notes play faster and the animated ball bounce faster.
The fact that the program uses the same features to create music and movement allows us to test whether emotion is really expressed the same way for music and movement. Does angry music have the same dynamics as angry movement? This would help explain why music can "move" us -- why humans everywhere dance to music and why music is so important for creating group cohesion (synchrony) and ritual.
We asked college students to create five different emotional expressions (angry, happy, sad, peaceful, and scared) using the sliders. We found that they placed the slider bars in a particular, distinct configuration for each emotion. Most importantly this configuration was the same regardless of whether they were trying to express that emotion in music or movement.
To find out whether these crossmodal emotional expressions are universal, we took our program to a remote tribal village in Cambodia. Villagers had never used computers before or been exposed to Western music and yet created the five emotional expressions in the same way as our Dartmouth college students. Thus, these emotional expressions are crosscultural and crossmodal. Perhaps, most importantly this study provides evidence for the fundamental link between music and movement -- they share a dynamic structure.
For the paper, click here. National Geographic also has a nice review of this study with figures, videos, and sound files here. Joe Hanson of it's Okay To Be Smart created a nice video for PBS about this study, here:
Sievers, B., Polansky, L., Casey, M., & Wheatley, T. (2012). Music and movement share a dynamic structure that supports universal expressions of emotion. Proceedings of the National Academy of Sciences.