The ‘Mozart effect’ is bunk. But your brain on music is still a wondrous thing.
The neurological signature of musicians’ brains is that of an ‘auditory-motor athlete.’
By Adriana Barton

In 1993, three dozen college students filed into a lab in Irvine, Calif., to take part in an unusual experiment. The lead researcher, Frances Rauscher, a red-haired woman in her late 30s and a former child prodigy, had abandoned her career as a concert cellist, burned out by the grind of performing gala recitals in Paris and New York. In her new life as an experimental psychologist, she dedicated herself to studying the cognitive benefits of music, especially Mozart.

For this small pilot study, she had selected Mozart’s Sonata for Two Pianos in D Major, K. 448, a work described by the musicologist Alfred Einstein (a cousin of Albert’s) as “one of the most profound and mature’’ of all Mozart’s compositions. Students in the lab spent 10 minutes listening to either Mozart or a relaxation tape or sitting in silence. Straight after, they completed puzzles from a standard intelligence test, such as picturing how to cut and fold paper into specific shapes. When Rauscher analyzed their scores, the results took her breath away. Just 10 minutes of Mozart seemed to improve their spatial reasoning by the equivalent of eight to nine IQ points. Although the gains evaporated after 10 to 15 minutes, when Rauscher described her study in a two-page letter in the journal Nature later that year, the media went wild.

Her results — dubbed the “Mozart effect’’ — inspired a best-selling book and a cottage industry of so-called brainpower products, including a slew of Baby Genius CDs. Rauscher, however, never claimed that listening to Mozart increases intelligence. She and her coauthor merely hypothesized that Wolfgang’s music “primed’’ different brain regions for abstract reasoning.

These nuances fell on deaf ears. “You can never control what the marketers will do,’’ she told the Los Angeles Times, as the Mozart fad took off. Mozart mania reached fever pitch in 1998, when Georgia Governor Zell Miller announced a proposal to provide every newborn with a classical music cassette tape or CD. “No one questions,’’ Miller declared, “that listening to music at a very early age affects the spatial-temporal reasoning that underlies math and engineering, and even chess.’’

On the contrary, legions of scientists questioned the notion that listening to Mozart could boost IQ. But what about playing an instrument?

In the three decades since Rauscher’s Mozart experiment, thousands of people have undergone brain scans and cognitive tests aimed at answering that question and identifying how music shapes our brains. In study after study, children and adults with extensive music training tend to outperform nonmusicians on tests of working memory, attention, and executive functioning, which is the higher-level thinking involved in problem-solving and switching between tasks. Learning an instrument at a young age has been linked to stronger auditory processing, emotional perception, and “stick-to-itiveness,’’ all of which may contribute to future success.

But here’s the hitch: Music training alone does not explain why children who play instruments show stronger reading skills and academic achievement. Children are shaped by a wide array of genetic, socioeconomic, and cultural dynamics. And music lessons aren’t cheap. Anyone studying their effects must account for the strong link between academic achievement and affluence.

This much we do know: Playing an instrument is a brain-twisting feat. Reading music involves translating symbols on the page into specific sounds in the flash of an eye. Performing without sheet music (“learning by heart’’) recruits muscle memory and several other types of recall. In just two and a half minutes of music, Bach’s cello prelude in G major has roughly 650 notes with different pitches, bowings, and musical inflections. If a cellist had to consciously remind themself how to play each note (this one is played with my third finger, on a down bow, etc.), they’d never pull it off.

With cognitive demands like these, it’s hard to imagine that playing an instrument wouldn’t have an impact on a child’s scholastic performance. Yet solid proof remains elusive.

In a 2020 study, a team of statisticians analyzed 54 studies of music training published from 1986 to 2019. Their meta analysis found no relationship between music lessons and enhanced cognitive skills or academic performance, regardless of the child’s age or amount of music training. The statisticians chalked up the benefits found in previous research to faulty interpretations of the data, along with possible “confirmation bias’’ — the tendency to find what you’re expecting to find. The team described efforts to enhance academic skills through music training as “pointless.’’

Canadian researchers have concluded that preexisting differences, such as conscientiousness and openness to new experience, likely explain the link between music training and higher grades.

Although playing an instrument doesn’t increase IQ, it can alter the structure and density of our gray and white matter. (Gray matter contains the neurons that help us think, talk, feel, and perceive, whereas white matter connects gray areas to one another and sends signals up and down the spinal cord.) As the late neurologist Oliver Sacks wrote: “Anatomists today would be hard put to identify the brain of a visual artist, a writer, or a mathematician, but they would recognize the brain of a professional musician without a moment’s hesitation.’’

When neurologists conducted the first MRI scans of musicians’ brains, starting in the early 1990s, they expected to find evidence of musical abilities in the brain’s right hemisphere and of language in the left. (Although both sides of the brain engage in everything we do, the left hemisphere tends to be more involved in verbal tasks while the right hemisphere excels in visual perception.) Musicians showed as much left-side dominance as nonmusicians. But the structure of the musicians’ brains revealed startling differences: namely, a thicker corpus callosum — the fibrous nerve bundle that sends brain signals back and forth between the two hemispheres — and more gray matter in the auditory, sensory, and motor areas.

A musician, declared the neurologist Gottfried Schlaug, “is basically an auditory-motor athlete.’’

Did these differences come from music training itself or were those born with a thicker corpus callosum simply more drawn to playing an instrument? In a landmark 2009 study, a group of American first-graders attended 15 months of private piano lessons and practiced regularly at home. A second group had a weekly school music class but no private lessons or home practice. All were closely matched in age, brain structure, and socioeconomic background. After 15 months, only the private piano lesson group showed the brain characteristics found in adult musicians. A separate study of adult identical twins found similar brain changes in those who played an instrument but not in their nonmusician siblings. Clearly, a musician’s brain comes from nurture, not nature.

Music wires the brain in specific ways, depending on the instrument we play. Pianists have extra gray matter in visual-spatial areas, used to figure out where objects are in space. Drummers have hyperefficient motor areas, allowing them to perform complex movements with far less brain activity than nonmusicians. And in classical string players, the left digits, used for fingering the notes, take up extra space on the brain’s cortical “map’’ for processing touch in distinct body parts.

Even the brains of musicians who don’t play instruments reveal a kind of rewiring. In a 2018 study, neuroscientists scanned the brains of professional beatboxers who use their voices to mimic percussion sounds. Most of the beatboxers got started at around age 14 — double the typical age for a professional pianist. Nevertheless, when beatboxers listened to tracks by a fellow performer, the brain area that controls mouth movements lit up. Although they lacked the thicker corpus callosum of an instrumentalist, the beatboxers showed functional brain changes that matched their musical skill set.

Whether brain changes like these offer cognitive benefits that spill over into other activities remains an area of intensive research. At the very least, music lessons can sharpen our auditory skills — an advantage that seems to linger even in adults who haven’t touched a musical instrument in years.

Fortunately, we don’t need to wait for more science to discover the pleasures of music-making. Each time we sit at a piano or pick up a guitar is a chance to tap into a universal source of comfort, emotional expression, and joy.

Adriana Barton is a science journalist and a former cellist. She is the author of “Wired for Music: A Search for Health and Joy Through the Science of Sound,’’ from which this article has been adapted.