In that first study, her team identified 11 adults who seemed likely to have truly amusia and subjected them to six tests that judged their perception of the melodic and temporal aspects of music, along with their musical memory (their ability to recognize songs). Her subjects all performed at least three standard deviations below the mean on at least two of the tests. That inability to recognize pitch, moreover, only applied to music -- not language. When the melody and lyrics of popular songs were presented separately, the amusic participants were generally able to recognize spoken lyrics, but were significantly impaired in their ability to tell whether they had heard a tune before.

Ability to recognize a popular song

It's been difficult for researchers to get over the idea that, with enough exposure to music, people born with amusia might somehow learn to listen. But even as music has become even more pervasive (think iPods), the condition persists. Last year, Peretz and her team looked into the potential to train young people with amusia, who they reasoned might have enough brain plasticity to be somewhat remediated. They gave 14 amusic 10- to 13-year-olds their basic test for music-hearing ability, then sent them home with MP3 players loaded with popular music (200 songs they found on the Internet, such as "No One" by Alicia Keys), which they were instructed to listen to for 30 minutes a day. Four weeks later, they were retested.

The kids tried. They ended up listening to their MP3 players for closer to 45 minutes a day. But at the end of the month, not only did they fail to improve on the tests, how poorly they scored correlated with how much music they reported listening to.

A new study published in the journal Brain takes it back a step by trying to figure out exactly where the brains of people with amusia go wrong. While subjecting participants to a basic melody-recognition test, researchers in Lyon, France studied their brain activity using magnetoencephalography (MEG) scanners. They found that amusic people's difficulties on the test stemmed from delayed or otherwise impaired functioning of two areas of the brain, the frontal and auditory cortexes, during the early encoding of melodic information. What's more, the researchers detected physical abnormalities in those brain areas. For example, they had more grey matter and less white matter than is usual in the frontal cortex. This "convergence of functional and structural brain differences" appears to explain people with congential amusia's inability to both process pitch and retain short-term memory of melodies.

"For the moment we cannot speak about remediation, cure, or treatment of amusia," one of the study's authors, Philippe Albouy, wrote to me in an email. But a next step could be to explore training programs that might improve people's pitch perception and memory -- those two basic skills essential to the ability to recognize music. They would probably have to be more focused than just making patients listen to more music. And while, sure, there are more life-and-death things we could be focusing on curing, understanding the neurological basis of amusia could help researchers understand other learning disorders, including the flip side of the coin: language impairments.

Even as the picture of what's going on in the brain becomes more clear, it's hard to really understand what it must be like to be completely tone deaf, just as, for people with amusia, it's probably hard to understand what the big deal is. A lot of people with amusia don't seem very distressed by their condition, but that could just be because they don't know what they're missing. The original participants in Peretz's study only identified themselves as unable to sing in tune because they had been informed of this inability by others. Still, the majority claimed not to appreciate music, with two going so far as to report finding music unpleasant and going out of their way to avoid it. And eight out of the eleven had difficulty dancing.

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