By Eva Briggs, MD
I’m lucky to live near a park that hosts weekly free concerts during the summer. When the music is going, you can look around and see people dancing, swaying, tapping their toes, nodding their heads or otherwise moving to the music.
There’s a universal irresistible urge to move when people listen to music. Scientists call it groove and it turns out that they’ve done some research on what leads to groove and how it affects the mind.
Music has been around for a long time. The earliest known musical instrument is a Neanderthal flute found in a Slovenian cave. It’s estimated to be 60,000 years old. The urge to move to music is found across cultures, with words for the phenomenon like “balanço” in Brazil, “nori” in Japanese and “lupfig” in Swiss German. Babies as young as 3-6 months old increase their movements in response to music.
All music is not created equal when it comes to its ability to stimulate movement. The degree of complexity of the rhythm turns out to be the key. Scientists have devised a formula to measure the degree of musical syncopation. Syncopation means that a stressed or accented beat does not fall where the listener expects.
Music that is too predictable rhythmically is less likely to get people moving. On the other hand, music that is too rhythmically complex doesn’t lead to groove, either. It’s the sweet spot in the middle that’s most effective.
Why is that? Scientists theorize that humans have an inborn desire for predictability. Moving along to the music is one way to make things predictable. When the rhythm is too simple there is no need to add predictability. And if it’s too complex it becomes impossible to add predictability. But somewhere in the middle it all comes together.
Interesting things happen inside the brain when people listen to music. Using neuroimaging, researchers found that the more pleasurable a musical passage, the higher the activity in brain centers associated with reward and motivation. And even when people are holding still, music that stimulates groove causes brain areas associated with movement to light up.
There are other factors causing groove. One is tempo — the speed of the musical beat. The optimum is 107 to 126 beats per minute. It turns out this is the tempo that DJs typically play at musical events. It’s also close to the preferred walking speed of two steps per second.
The vestibular system — how we perceive balance — is also probably involved in groove.
In a study of dance music, researchers turned a very low frequency bass beat on and off. The sound was too low for people to hear but still perceptible by the body’s vestibular system. People danced more when the low bass was turned on. Other studies show that when music is played over speakers that produce more vibrations, people increase their body movement, tapping force and perception of groove.
Since music has been around for so long and in every culture, what is its purpose? One theory is that music synchronizes people to one another. That strengthens social bonds.
So, get out there and listen to some live music before summer is over!
Eva Briggs is a retired medical doctor who practiced in Central New York for several decades. She lives in Marcellus.