Clip: Music of the Hemispheres
- Why not start out the new year by considering why we like music?
Interesting story in the New York Times this weekend.
Music of the Hemispheres
By CLIVE THOMPSON
Published: December 31, 2006
"Listen to this," Daniel Levitin said. "What is it?" He hit a button
on his computer keyboard and out came a half-second clip of music. It
was just two notes blasted on a raspy electric guitar, but I could
immediately identify it: the opening lick to the Rolling Stones'
Then he played another, even shorter snippet: a single chord struck
once on piano. Again I could instantly figure out what it was: the
first note in Elton John's live version of "Benny and the Jets."
Dr. Levitin beamed. "You hear only one note, and you already know who
it is," he said. "So what I want to know is: How we do this? Why are
we so good at recognizing music?"
This is not merely some whoa-dude epiphany that a music fan might have
while listening to a radio contest. Dr. Levitin has devoted his career
to exploring this question. He is a cognitive psychologist who runs
the Laboratory for Music Perception, Cognition and Expertise at McGill
University in Montreal, perhaps the world's leading lab in probing why
music has such an intense effect on us.
"By the age of 5 we are all musical experts, so this stuff is clearly
wired really deeply into us," said Dr. Levitin, an eerily
youthful-looking 49, surrounded by the pianos, guitars and enormous
16-track mixers that make his lab look more like a recording studio.
This summer he published "This Is Your Brain on Music" (Dutton), a
layperson's guide to the emerging neuroscience of music. Dr. Levitin
is an unusually deft interpreter, full of striking scientific trivia.
For example we learn that babies begin life with synesthesia, the
trippy confusion that makes people experience sounds as smells or
tastes as colors. Or that the cerebellum, a part of the brain that
helps govern movement, is also wired to the ears and produces some of
our emotional responses to music. His experiments have even suggested
that watching a musician perform affects brain chemistry differently
from listening to a recording.
Dr. Levitin is singular among music scientists for actually having
come out of the music industry. Before getting his Ph.D. he spent 15
years as a record producer, working with artists ranging from the Blue
Öyster Cult to Chris Isaak. While still in graduate school he helped
Stevie Wonder assemble a best-of collection; in 1992 Dr. Levitin's
sensitive ears detected that MCA Records had accidentally used
third-generation backup tapes to produce seven Steely Dan CDs, and he
embarrassed the label by disclosing it in Billboard magazine. He has
earned nine gold and platinum albums, which he tucks in corners of his
lab, office and basement at home. "They look a little scary when you
put them all in one place, so I spread them around," he said.
Martin Grant, the dean of science at McGill, compares Dr. Levitin's
split professional personality to that of Brian Greene, the pioneering
string-theory scientist who also writes mass-market books. "Some
people are good popularizers, and some are good scientists, but not
usually both at once," Dr. Grant said. "Dan's actually cutting edge in
Scientifically, Dr. Levitin's colleagues credit him for focusing
attention on how music affects our emotions, turf that wasn't often
covered by previous generations of psychoacousticians, who studied
narrower questions about how the brain perceives musical sounds. "The
questions he asks are very very musical, very concerned with the fact
that music is an art that we interact with, not just a bunch of
noises," said Rita Aiello, an adjunct professor in the department of
psychology at New York University.
Ultimately, scientists say, his work offers a new way to unlock the
mysteries of the brain: how memory works, how people with autism
think, why our ancestors first picked up instruments and began to
play, tens of thousands of years ago.
DR. LEVITIN originally became interested in producing in 1981, when
his band — a punk outfit called the Mortals — went into the recording
studio. None of the other members were interested in the process, so
he made all the decisions behind the board. "I actually became a
producer because I saw the producers getting all the babes," he said.
"They were stealing them from the guitarists." He dropped out of
college to work with alternative bands.
Producers, he noted, were able to notice impossibly fine gradations of
quality in music. Many could identify by ear the type of amplifiers
and recording tape used on an album.
"So I started wondering: How was the brain able to do this?" Dr.
Levitin said. "What's going on there, and why are some people better
than others? And why is music such an emotional experience?" He began
sitting in on neuroscience classes at Stanford University.
"Even back then, Dan was never satisfied with the simple answer," said
Howie Klein, a former president of Reprise and Sire Records. "He was
always poking and prodding."
By the '90s Dr. Levitin was disenchanted with the music industry.
"When they're dropping Van Morrison and Elvis Costello because they
don't sell enough records," he said, "I knew it was time to move on."
Academic friends persuaded him to pursue a science degree. They bet
that he would have good intuitions on how to design music experiments.
They were right. Traditionally music psychologists relied on "simple
melodies they'd written themselves," Dr. Levitin said. What could that
tell anyone about the true impact of powerful music?
For his first experiment he came up with an elegant concept: He
stopped people on the street and asked them to sing, entirely from
memory, one of their favorite hit songs. The results were
astonishingly accurate. Most people could hit the tempo of the
original song within a four-percent margin of error, and two-thirds
sang within a semitone of the original pitch, a level of accuracy that
wouldn't embarrass a pro.
"When you played the recording of them singing alongside the actual
recording of the original song, it sounded like they were singing
along," Dr. Levitin said.
It was a remarkable feat. Most memories degrade and distort with time;
why would pop music memories be so sharply encoded? Perhaps because
music triggers the reward centers in our brains. In a study published
last year Dr. Levitin and group of neuroscientists mapped out
Observing 13 subjects who listened to classical music while in an
M.R.I. machine, the scientists found a cascade of brain-chemical
activity. First the music triggered the forebrain, as it analyzed the
structure and meaning of the tune. Then the nucleus accumbus and
ventral tegmental area activated to release dopamine, a chemical that
triggers the brain's sense of reward.
The cerebellum, an area normally associated with physical movement,
reacted too, responding to what Dr. Levitin suspected was the brain's
predictions of where the song was going to go. As the brain
internalizes the tempo, rhythm and emotional peaks of a song, the
cerebellum begins reacting every time the song produces tension (that
is, subtle deviations from its normal melody or tempo).
"When we saw all this activity going on precisely in sync, in this
order, we knew we had the smoking gun," he said. "We've always known
that music is good for improving your mood. But this showed precisely
how it happens."
The subtlest reason that pop music is so flavorful to our brains is
that it relies so strongly on timbre. Timbre is a peculiar blend of
tones in any sound; it is why a tuba sounds so different from a flute
even when they are playing the same melody in the same key. Popular
performers or groups, Dr. Levitin argued, are pleasing not because of
any particular virtuosity, but because they create an overall timbre
that remains consistent from song to song. That quality explains why,
for example, I could identify even a single note of Elton John's
"Benny and the Jets."
"Nobody else's piano sounds quite like that," he said, referring to
Mr. John. "Pop musicians compose with timbre. Pitch and harmony are
becoming less important."
Dr. Levitin dragged me over to a lab computer to show me what he was
talking about. "Listen to this," he said, and played an MP3. It was
pretty awful: a poorly recorded, nasal-sounding British band
performing, for some reason, a Spanish-themed ballad.
Dr. Levitin grinned. "That," he said, "is the original demo tape of
the Beatles. It was rejected by every record company. And you can see
why. To you and me it sounds terrible. But George Martin heard this
and thought, 'Oh yeah, I can imagine a multibillion-dollar industry
built on this.'
"Now that's musical genius."
THE largest audience that Dr. Levitin has performed in front of was
1,000 people, when he played backup saxophone for Mel Tormé. Years of
being onstage piqued Dr. Levitin's interest in another aspect of
musical experience: watching bands perform. Does the brain experience
a live performance differently from a recorded one?
To find out, he and Bradley Vines, a graduate student, devised an
interesting experiment. They took two clarinet performances and played
them for three groups of listeners: one that heard audio only; one
that saw a video only; and one that had audio and video. As each group
listened, participants used a slider to indicate how their level of
tension was rising or falling.
One rapid, complex passage caused tension in all groups, but less in
the one watching and listening simultaneously. Why? Possibly, Dr.
Levitin said, because of the performer's body language: the
clarinetist appeared to be relaxed even during that rapid-fire
passage, and the audience picked up on his visual cues. The reverse
was also true: when the clarinetist played in a subdued way but
appeared animated, the people with only video felt more tension than
those with only audio.
In another, similar experiment the clarinetist fell silent for a few
bars. This time the viewers watching the video maintained a higher
level of excitement because they could see that he was gearing up to
launch into a new passage. The audio-only listeners had no such visual
cues, and they regarded the silence as much less exciting.
This spring Dr. Levitin began an even more involved experiment to
determine how much emotion is conveyed by live performers. In April he
took participants in a Boston Symphony Orchestra concert — the
conductor Keith Lockhart, five of the musicians and 15 audience
members — and wired them with sensors to measure their state of
arousal, including heart rate, body movements and muscle tension.
At one point during the performance Mr. Lockhart swung his wrist with
such force that a sensor attached to his cuff went flying off. Dr.
Levitin's team tried to reattach it with duct tape, until the
conductor objected — "Did you just put duct tape on an Armani?" he
asked — and lighter surgical tape was used instead.
The point of the experiment is to determine whether the conductor
creates noticeable changes in the emotional tenor of the performance.
Dr. Levitin says he suspects there's a domino effect: the conductor
becomes particularly animated, transmits this to the orchestra and
then to the audience, in a matter of seconds. Mr. Lockhart is
skeptical. "As a conductor," he said, "I'm a causatory force for
music, but I'm not a causatory force for emotion." But Dr. Levitin is
still crunching the data.
"It might not turn out to be like that," he said, "But wouldn't it be
cool if it did?"
Dr. Levitin's work has occasionally undermined some cherished beliefs
about music. For example recent years have seen an explosion of "Baby
Mozart" videos and toys, based on the idea — popular since the '80s —
that musical and mathematical ability are inherently linked.
But Dr. Levitin argued that this could not be true, based on his study
of people with Williams syndrome, a genetic disorder that leaves
people with low intelligence. Their peak mental capacities are
typically those of young child, with no ability to calculate
quantities. Dr. Levitin once asked a woman with Williams to hold up
her hand for five seconds; she left it in the air for a minute and a
half. "No concept of time at all," he said, "and definitely no math."
Yet people with Williams possess unusually high levels of musical
ability. One Williams boy Dr. Levitin met was so poorly coordinated he
could not open the case to his clarinet. But once he was holding the
instrument, his coordination problems vanished, and he could play
fluidly. Music cannot be indispensably correlated with math, Dr.
Levitin noted, if Williams people can play music. He is now working on
a study that compares autistics — some of whom have excellent
mathematical ability, but little musical ability — to people with
Williams; in the long run, he said, he thinks it could help shed light
on why autistic brains develop so differently.
Not all of Dr. Levitin's idea have been easily accepted. He argues,
for example, that music is an evolutionary adaptation: something that
men developed as a way to demonstrate reproductive fitness. (Before
you laugh, consider the sex lives of today's male rock stars.) Music
also helped social groups cohere. "Music has got to be useful for
survival, or we would have gotten rid of it years ago," he said.
But Steven Pinker, a cognitive scientist at Harvard known for his
defense of evolutionary psychology, has publicly disparaged this idea.
Dr. Pinker has called music "auditory cheesecake," something pleasant
but not evolutionarily nutritious. If it is a sexual signal for
reproduction, then why, Dr. Pinker asked, does "a 60-year-old woman
enjoy listening to classical music when she's alone at home?" Dr.
Levitin wrote an entire chapter refuting Dr. Pinker's arguments; when
I asked Dr. Pinker about Dr. Levitin's book he said he hadn't read it.
Nonetheless Dr. Levitin plugs on, and sometimes still plugs in. He
continues to perform music, doing several gigs a year with Diminished
Faculties, a ragtag band composed entirely of professors and students
at McGill. On a recent December afternoon members assembled in a
campus ballroom to do a sound check for their performance that evening
at a holiday party. Playing a blue Stratocaster, Dr. Levitin crooned
the Chris Isaak song "Wicked Game." "I'm not a great guitarist, and
I'm not a great singer," he said.
But he is not bad, either, and still has those producer's ears. When
"Wicked Game" ended, the bass player began noodling idly, playing the
first few notes of a song that seemed instantly familiar to all the
younger students gathered. "That's Nirvana, right?" Dr. Levitin said,
cocking his head and squinting. " 'Come As You Are.' I love that