ELIZABETH WEST MARVIN can always tell which music students have perfect
pitch. They don’t necessarily play any differently from her other students, and
they may not always lead the chorus. But they are the ones who immediately get
distracted when the fluorescent lights above their heads start vibrating with an
electrical hum somewhere between B and B-flat.
The uncanny, if sometimes distracting, ability to name a solitary note out of
the blue, without any other notes for reference, is a prized musical
talent—and a scientific mystery. Musicians with perfect pitch—or, as
many researchers prefer to call it, absolute pitch—can often play pieces
by ear, and many can transcribe music brilliantly. That’s because they perceive
the position of a note in the musical stave—its pitch—as clearly as
the fact that they heard it. Hearing and naming the pitch go hand in hand.
By contrast, most musicians follow not the notes, but the relationships
between them. They may easily recognise two notes as being a certain number of
tones apart, but could name the higher note as an E only if they are told the
lower one is a C, for example. This is relative pitch. Useful, but much less
mysterious.
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For centuries, absolute pitch has been thought of as the preserve of the
musical elite. Some estimates suggest that maybe fewer than 1 in 2000 people
possess it. But a growing number of studies, from speech experiments to brain
scans, are now suggesting that a knack for absolute pitch may be far more
common, and more varied, than previously thought. “Absolute pitch is not an all
or nothing feature,” says Marvin, a music theorist at the University of
Rochester in New York state. Some researchers even claim that we could all
develop the skill, regardless of our musical talents. And their work may finally
settle a decades-old debate about whether absolute pitch depends on melodious
genes—or early music lessons.
Music psychologist Diana Deutsch at the University of California in San Diego
is the leading voice. Last month at the Acoustical Society of America meeting in
Columbus, Ohio, Deutsch reported a study that suggests we all have the potential
to acquire absolute pitch—and that speakers of tone languages use it every
day. A third of the world’s population—chiefly people in Asia and
Africa—speak tone languages, in which a word’s meaning can vary depending
on the pitch a speaker uses.
Deutsch and her colleagues asked seven native Vietnamese speakers and 15
native Mandarin speakers to read out lists of words on different days. The
chosen words spanned a range of pitches, to force the speakers to raise and
lower their voices considerably. By recording these recited lists and taking the
average pitch for each whole word, the researchers compared the pitches used by
each person to say each word on different days.
Both groups showed strikingly consistent pitch for any given word—often
less than a quarter-tone difference between days. “The similarity,” Deutsch
says, “is mind-boggling.” It’s also, she says, a real example of absolute pitch.
As babies, the speakers learnt to associate certain pitches with meaningful
words—just as a musician labels one tone A and another B—and they
demonstrate this precise use of pitch regardless of whether or not they have had
any musical training, she adds.
Deutsch isn’t the only researcher turning up everyday evidence of absolute
pitch. At least three other experiments have found that people can launch into
familiar songs at or very near the correct pitches. Some researchers have
nicknamed this ability “absolute memory”, and they say it pops up in other
senses, too. In a 1994 study, for example, Svein Magnussen and Stein Dyrnes of
the University of Oslo in Norway found an absolute memory for visual images,
showing that people could pick out complex black-and-white line designs they had
seen hours or days earlier from a selection of very similar ones.
Given studies like these, the real mystery is why we don’t all have absolute
pitch, says cognitive psychologist Daniel Levitin of McGill University in
Montreal. “I don’t have to run to a rainbow and find red to tell you that a
tomato is red,” Levitin says. “There are 10 basic colours that everyone can name
immediately. Well, there are 12 basic pitches. If we can label all those
colours, why can’t we label all those pitches?”
Levitin suspects he knows the answer. Absolute pitch, he says, is really a
two-step process: pitch memory and pitch labelling. It’s not that people with
absolute pitch are genetically endowed with a keener sense of pitch perception,
Levitin says—after all, many of us can recall a note nearly perfectly
immediately after we hear it. But people with absolute pitch automatically
connect the memory of a pitch with a label. Some even describe different pitches
as having distinct “colours” or “characters”.
Lacking absolute pitch, most of us can’t make that connection—labelling
a note as “D”, for example. But do the connections and labels get hammered in
during music lessons, or are some babies just born with a flair for identifying
pitch? That’s a hard question to answer, since musical parents often pass a
passion for music—as well as their genes—on to their children.
Over the past decade, researchers have confirmed that absolute pitch often
runs in families. Nelson Freimer of the University of California in San
Francisco, for example, is just completing a study that he says strongly
suggests the right genes help create this brand of musical genius. Freimer gave
tone tests to people with absolute pitch and to their relatives. He also tested
several hundred other people who had taken early music lessons. He found that
relatives of people with absolute pitch were far more likely to develop the
skill than people who simply had the music lessons. “There is clearly a familial
aggregation of absolute pitch,” Freimer says.
Blossoming talent
Freimer says some children are probably genetically predisposed toward
absolute pitch—and this innate inclination blossoms during childhood music
lessons. Indeed, many researchers now point to this harmony of nature and
nurture to explain why musicians with absolute pitch show different levels of
the talent. “The early learning period—from about three to six years of
age—is critical,” says Marvin. But lucky genes probably help, she
adds.
Indeed, researchers are finding more and more evidence suggesting music
lessons are critical to the development of absolute pitch. In a survey of 2700
students in American music conservatories and college programmes, New York
University geneticist Peter Gregersen and his colleagues found that a whopping
32 per cent of the Asian students reported having absolute pitch, compared with
just 7 per cent of non-Asian students. While that might suggest a genetic
tendency towards absolute pitch in the Asian population, Gregersen says that the
type and timing of music lessons probably explains much of the difference.
For one thing, those with absolute pitch started lessons, on average, when
they were five years old, while those without absolute pitch started around the
age of eight. Moreover, adds Gregersen, the type of music lessons favoured in
Asia, and by many of the Asian families in his study, such as the Suzuki method,
often focus on playing by ear and learning the names of musical notes, while
those more commonly used in the US tend to emphasise learning scales in a
relative pitch way. In Japanese preschool music programmes, he says, children
often have to listen to notes played on a piano and hold up a coloured flag to
signal the pitch. “There’s a distinct cultural difference,” he says.
If the right genes and music lessons do prompt people to label tones in a
fundamentally different way, then this cognitive difference should show up in
their brains. As indeed it does. In a 1998 study, neuroscientist Robert Zatorre
of the Montreal Neurological Institute in Canada ran positron emission
tomography (PET) scans of musicians with and without absolute pitch while they
listened to tones.
When asked to label a tone, the musicians lacking absolute pitch had a flash
of brain activity in the right frontal cortex—an area associated with
working memory and comparing incoming sensory information with memories. By
contrast, the musicians who had absolute pitch could identify tones without
accessing working memory at all. Instead, they showed a spark of brain activity
high in the left frontal cortex—a region related to long-term memory.
Zattore suggests that the absolute pitch users were tapping into a more deeply
ingrained pitch template that they developed during childhood lessons.
A study led by musicologist Laura Bischoff of Shepherd College in West
Virginia also shows that people with the strongest absolute pitch skills can
name notes without working memory. Bischoff and her colleagues gave 32 music
students—half of whom had absolute pitch—a series of tone tests
while the students wore a jumble of scalp electrodes. The researchers were
looking for a working memory marker: the P300, a positively charged waveform
that flashes across the brain 300 milliseconds after a surprising stimulus. The
P300 is thought to indicate a comparison of incoming sensory stimuli—such
as a new tone—with memorised information, in this case a musical
scale.
During one test, the students listened to a typical scale, trying to guess
whether the note being played fitted within the scale. At first, the notes would
build predictably, neatly forming a scale in the key of C. But then a tone would
jump out of scale, falling unexpectedly flat or sharp. Scrambling to name that
errant tone, the students without absolute pitch showed a P300 surge, as
expected, while most of the students that had absolute pitch did not.
But the experiment also showed how varied a talent absolute pitch can be.
Four of Bischoff’s absolute pitch students showed brain wave patterns more like
those in the control group. Further tests revealed that these absolute pitch
students alternated between absolute and relative pitch, depending on the task
at hand.
The lesson, Bischoff says, is that absolute pitch is not a one-size-fits-all
talent. Some people have an acute sense of absolute pitch, while others show
just a hint of the skill. And some absolute pitch possessors use it only
occasionally, flipping back to relative pitch when that skill is more
useful.
A bit of both
That doesn’t surprise Philip Chang, a music theory graduate student at
Rochester. While he’s had absolute pitch since he was a child, Chang has also
had training that hones relative pitch skills—practising scales,
recognising intervals and so on. “I just use what’s helpful,” he says.
But can anyone develop absolute pitch? Bischoff thinks so. “Our studies tie
right in with the idea that we all have this latent absolute pitch ability, but
we can’t get fully bloomed absolute pitch without early childhood training,”
says Bischoff.
But some scientists are more cautious. After all, if everyone remembered
pitches, but just couldn’t label them, we’d immediately know if something was
played in an unusual key, or if two songs started on the same note, says
psychologist Andrea Halpern of Bucknell University in Lewisburg, Pennsylvania.
These feats, she says, are reserved for people with absolute pitch.
Similarly, linguists are wary of the idea that consistently speaking in a
given pitch range somehow reflects absolute pitch. People naturally settle into
a comfortable range while talking, says Rebecca Herman, a linguist at Indiana
University. Deutsch counters that this “comfort zone” argument can’t explain the
exceedingly small differences in pitch among her speakers.
Indeed, Deutsch predicts that further studies will reveal absolute
pitch—in its imperfect, latent form—inside all of us. The Western
emphasis on relative pitch simply obscures it, she contends. “It’s very likely
that scientists will end up concluding that we’re all born with the potential to
acquire very fine-grained absolute pitch. It’s really just a matter of life
getting in the way.”
Humans may have to search high and low for traces of absolute pitch, but
other animals flaunt the talent. Researchers have found that bats, wolves,
gerbils and birds all sometimes use forms of absolute pitch to spot possible
mates—or meals—amid nature’s cacophony.
Songbirds, in particular, put humans to shame. In a 1998 study, psychologist
Ron Weisman at Queen’s University in Ontario, Canada, pitted 10 male zebra
finches against 10 accomplished musicians. The birds had to decide whether to
fly to a feeder that opened only when tones within four narrow frequency ranges
were played, while the humans pushed a button to indicate whether a pitch was in
one of the designated ranges—and won prize money for correct answers.
Towards the end of the experiment, Weisman says, the feathered participants
identified pitch correctly 85 per cent of the time, while our species succeeded
just over half the time. “We didn’t have the heart to tell these skilled
musicians that their performance was abysmal compared to a bunch of birds,” says
Weisman.
But there’s good reason for these creatures’ virtuoso performances: zebra
finches recognise members of their own species by the pitch range of their
songs. “And if you’ve ever heard birds in a dawn chorus, you know how hard it is
to distinguish one bird among the crowd,” says Weisman. Zebra finches can
identify the absolute pitch of a mate’s song up to 100 metres away, he says.
Songbirds and songwriters do have some things in common, though. Both birds
and humans with absolute pitch can often switch to relative pitch as well,
Weisman says. What’s more, the birds hone their ear for pitch during youth, when
they listen for the calls of family members and neighbours. There are some music
lessons, Weisman notes, that really pay off.
The call of the wild
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For more information about absolute pitch, visit
www.provide.net/~bfield/abs_pitch. html. Levitin’s work is described at
http:// cm.stanford.edu/~levitin/AP_casys.html, and details of the UCSF
study and an opportunity to test your own pitch perception can be found at
http://www.perfectpitch.org