How do musicians intuitively move and play together as one single unit? In a new study, Canadian researchers used a novel technique to better understand how band members synchronize their musical expression and movements during a free-flowing performance.

The results, published in the journal Scientific Reports, show that playing with greater emotion and expression may play a large role in synchronizing the music, as this allows the musicians to better predict one another’s movements.

“Successfully performing music with a group is a highly complex endeavor,” said Dr. Laurel Trainor, the senior author on the study and director of the LIVELab at McMaster University in Ontario, Canada, where the work was conducted.

“How do musicians coordinate with each other to perform expressive music that has changes in tempo and dynamics? Accomplishing this relies on predicting what your fellow musicians will do next so that you can plan the motor movements so as to express the same emotions in a coordinated way. If you wait to hear what your fellow musicians will do, it is too late.”

For the study, McMaster University researchers turned to the acclaimed chamber music ensemble Gryphon Trio. Each performer was fitted with motion capture markers to track their movements while the musicians played happy or sad musical excerpts, once with musical expression, once without.

Using mathematical techniques, the research team measured how much the movements of each musician were predicting the movements of the others.

Whether they were portraying joy or sadness, the musicians predicted each others’ movements to a greater extent when they played expressively, compared to when they played with no emotion.

“Our work shows we can measure communication of emotion between musicians by analyzing their movements in detail, and that achieving a common emotion expression as a group requires a lot of communication,” said graduate student Andrew Chang, the lead author on the study.

Researchers suggest this new technique can be applied to other situations, such as communication between non-verbal patients and their family and caregivers. They are also testing the method in a study on romantic attraction.

“The early results indicate that communication measured in body sway can predict which couples will want to see each other again,” said Chang.

Source: McMaster University