“We think it’s almost universal,” said Takahide Etani, a resident physician at the Japanese Red Cross Ashikaga Hospital who co-authored a 2024 study of neuroscience and psychology research on groove. Etani said many other countries have words that express a similar idea, such as “nori” in Japanese, “balanço” in Brazilian Portuguese and “svängig” in Swedish.
Research in psychology and neuroscience suggests that the phenomenon of groove reveals something fundamental about how our brains work: We like to try to predict how music is going to play out, and we move to help us make that prediction.
When the musical rhythm is not completely predictable, it invites us to move and “fill the rhythm”, “Music forces us to move to be whole, in a sense,” said Maria Witek, an associate professor of music at the University of Birmingham in Britain who researches musical cognition.
The power of groove is that it “makes music a distributed process in which we actively participate and sort of blurs the line between music, body and mind,” she said.
Groovy music is just unpredictable enough
The term “groove” is historically linked to the music of the African-American and Cuban diaspora, says Tomas Matthews, a postdoctoral researcher in clinical medicine at the Center for Music in the Brain at Aarhus University. “Groove-based” music genres include funk, hip-hop, jazz, and Afro-Cuban music. Musicians also use the term “groove” in a broader context, for example to describe a rhythmic part or to feel part of a group when playing. Scientists, on the other hand, use the term more narrowly to refer to the pleasurable urge to move to the rhythm of the music.
But not all music moves us. One of the key elements of music seems to be rhythmic complexity.
Research has consistently reported an inverted U-shaped relationship between subjective reports of groove and syncopation — interruptions in the regular time signature of the music, and an element of rhythmic complexity.
People tend to find that music with moderate rhythmic complexity elicits more groove sensations than music with a low or high rhythm.
There seems to be a sweet spot for predictability and complexity in music: too little complexity and it’s boring – no need to predict anything. Too much complexity and it’s too difficult – we can’t make sense of what we’re listening to, much less predict what comes next.
“We need some consistency to be able to move forward, but if it’s too irregular, we can’t even predict where the rhythm is,” Witek said.
Researchers hypothesize that one of the brain’s main functions is to predict what the world will hold for us and compare it to what actually happens.
If something doesn’t match the brain’s prediction, like an unexpected syncopation in a song, we get a prediction error.
“The idea is that we have some kind of fundamental desire to minimize prediction errors,” Matthews said. Being able to make accurate predictions about the world increases survival, he said.
The reason we tend to be lulled by music rather than the murmur of a brook or a lecture is that music has more predictable rhythms than nature sounds or human speech. Music has a time signature that we can predict, but the notes of the song can deviate from it, adding to its complexity and the difficulty of predicting it.
Moving to the beat of the music—whether by clapping, nodding, or dancing—is one way to add new sensory input that can minimize prediction error by reinforcing the underlying musical time signature.
But with just the right amount of complexity, trying to figure out what comes next becomes enjoyable.
“We like challenges,” said Matthews, who hypothesized in a recent paper that the process of minimizing prediction errors in music is inherently rewarding. “We’re drawn to something that’s challenging and not just perfectly regular.”
What a brain in motion looks like
Groovy sounds make the brain react differently.
In a 2020 neuroimaging study, Matthews, Witek, and their colleagues asked 54 subjects to listen to musical sequences of piano chords of medium or high rhythmic complexity and observed how brain activity changed in response.
Subjects reported experiencing stronger sensations, ranging from groove to medium complexity. In brain scans, how pleasant the subjects judged the sounds to be was correlated with activity in the ventral striatum, which receives dopamine and is important for reward-related behavior and motivation.
The researchers also found increased neural activity in areas of the brain involved in movement or movement timing, including the premotor area, basal ganglia, and supplementary motor area. Notably, these brain areas remained lit under brain scans even when the subjects were not moving and were linked to their self-reported urge to move.
There is a “privileged connection” between the auditory system and the brain’s motor system to control movement based on timing, Matthews said.
In a 2018 study, Etani and his colleagues reported that the optimal tempo for creating groove is between 107 and 126 beats per minute. Interestingly, this tempo is similar to what DJs tend to play at music events and is akin to our preferred walking speed of about two steps per second, Etani said.
Interestingly, the vestibular system, which controls balance, may also be essential to groove.
A 2022 study followed people attending an electronic music concert. During the show, researchers periodically turned on a very low-frequency bass sound that people can’t consciously hear but can be processed by the vestibular system. They found evidence that the deep bass in dance music may be a key element in getting people to dance: When the low-frequency bass was turned on, participants moved an average of 11.8% more.
Music creates connections and blurs boundaries
Music is often a communal experience that brings people together.
Groove can help us sync not only our brains and bodies with the music, but also with each other.
“I think the social bonding effect of music is related to the feeling or experience of the groove,” Etani said.
People who listen to the same music move together, and research has shown that synchronicity between individuals predicts their degree of similarity and prosocial behavior. Music may thus play an important role in strengthening social bonds.
If we all move to the same beat, that line between “you, the music and the people around you becomes blurred,” Witek said.
Do you have a question about human behavior or neuroscience? BrainMatters@washpost.com and we may answer it in a future column.