Can you feel the groove?

Most people can identify what makes music groovy — it has a swing to it, something that makes you want to tap your feet or snap your fingers. Utilized by hip-hop/soul artists like D’Angelo, Questlove, and J Dilla, or funk artists like James Brown, the distinct off-beat rhythms of groovy music keep listeners moving along.

To understand how people perceive the tiny timing differences that drive groove-based music, Câmara et al. measured participant responses to two musical timing concepts crucial to groove: asynchrony and non-isochrony.

“Previous psychophysical studies often used more simplified rhythmic stimuli such as clicks, isolated tones, or single instruments,” said author Guilherme Schmidt Câmara. “We wanted to further bridge that experimental tradition with more realistic musical contexts by using a multi-instrumental funk groove modeled partly on James Brown-style rhythm sections.”

Participants listened to musical samples that simulated the groovy rhythms with different timing manipulations, and the researchers tracked the listeners’ behavioral and pupillary responses to determine the just-noticeable difference (JND) threshold of groove.

“JND thresholds tell us how much a musical timing pattern can vary before listeners actually notice that something has changed,” Câmara said. “In groove-based music, this is especially relevant because many important expressive nuances occur at extremely small timescales — often just a few tens of milliseconds.”

Their findings show that listeners were highly sensitive to some types of micro timing differences, especially in percussion instruments, but their responses also depended on instrument and musical training.

“This helps explain why certain timing manipulations can strongly shape musical feel without necessarily sounding obviously ‘wrong,’” Câmara said. “More broadly, the results highlight how finely tuned human auditory perception is to subtle timing information, particularly in rhythmically rich musical environments.”

Source: “Just noticeable difference thresholds of asynchrony and non-isochrony in a multi-instrumental groove-based context,” by Guilherme Schmidt Câmara, Connor Spiech, Sandra Solli, Birger Bang, Olga Rogulina, Bruno Laeng, and Anne Danielsen, The Journal of the Acoustical Society of America (2026). The article can be accessed at https://doi.org/10.1121/10.0043887 .