IT DOESN’T take a musical genius to recognise the differences between performances by Arthur Rubinstein and Duke Ellington. They were both prominent pianists in the 20th century, but were known for two distinct genres. While the upbeat swing of Ellington’s “It Don’t Mean a Thing (If It Ain’t Got That Swing)” is the epitome of jazz, Rubinstein and his world-renowned recordings of nearly every work by Frédéric Chopin have a special place in the classical world. But it appears the differences between these musicians may have actually extended beyond their scores and into their brains. 

New research from the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, shows that jazz and classical musicians’ brain activity is different—even when they’re tackling the same score. In a sense, it comes down to different priorities, dictated by a musician’s native genre. While the improvisation in jazz requires a focus on harmonies and being comfortable adapting to unexpected musical changes, classical musicians learn to emphasise technique so that they can perform music as the composer intended. 

The team of researchers monitored the brains of 15 jazz pianists and 15 classical pianists as they copied a chord progression broadcast onto a screen in front of them. But there were two key twists. Any given chord progression could include unusual harmonies and/or unexpected finger placements. “With all these conditions, we could compare the brain signals evoked by playing the irregular harmony or irregular fingering with the signal evoked by playing correct chords (used as a baseline),” explained Roberta Bianco, one of the authors of the study.

Using EEG sensors to record the brain’s electrical activity, the researchers discovered that when faced with an unexpected order of the chords, the classical pianists experienced an increase in their brains’ theta-band activity, a type of electrical brain wave, which typically happens when someone is faced with conflict. The conflict reaction appeared to delay their playing compared with the jazz pianists, whose brains were able to reprogram quickly to play the requested chord. Ms Bianco says the reason may be because the jazz pianists were used to harmonic surprises and could adjust their thinking and play without hesitation. “They were kind of ready to play anything, while classical pianists would definitely expect a tonic chord at the end,” she says. 

Alternatively, the classical pianists made fewer mistakes compared with their musical peers when matching the peculiar finger placements on the chords, likely due to them focusing on this aspect of performance. The researchers discovered neural evidence (indicated through a decrease in beta oscillations, another type of electrical brain wave, which typically happens when the brain considers an action erroneous) that the classical pianists were paying more attention to the fingering, while the jazz pianists were paying more attention to the harmonies. While the oscillations decreased for jazz pianists during harmonic irregularities, it decreased for classical pianists during fingering irregularities, indicating they were each focused on these different aspects and thus more sensitive to violations in them.

The study states: “These findings demonstrate that specific demands and action focus of training lead to differential weighting of hierarchical action planning. This suggests different enduring markers impressed in the brain when a musician practices one or the other style.” In fact, even after the experiment was completed, Ms Bianco says there were differences in the way the musicians informally reacted to it. While some jazz players made an offhanded comment about the irregularities in the harmony, some classical musicians remarked on the odd finger placements.

There have been multiple reports documenting how musical training impacts brains, boosting everything from memory and problem solving to the ability to regulate behaviour. But the fact that training in different genres results in a different musical brain clarifies just how distinct these musical styles are, and why it is the rare musician who tackles classical and jazz in the same programme. In a 1997 article in Piano and Keyboard magazine, jazz pianist Keith Jarrett was asked if he’d consider doing a concert with both jazz and classical music. He replied: “No, that’s what I think is hilarious. I mean that is true insanity.”