Just reposting excerpts from a Yahoo news article.
Headline: One gene may be key to coveted perfect pitch
By Julie Steenhuysen
CHICAGO (Reuters) - Musicians and singers work for years to develop their sense of pitch but few can name a musical note without a reference tone. U.S. researchers on Monday said one gene may be the key to that coveted ability.
Only 1 in 10,000 people have perfect or absolute pitch, the uncanny ability to name the note of just about any sound without the help of a reference tone.
Dr. Jane Gitschier's (University of California, San Francisco) study appears in the journal Proceedings of the National Academy of Sciences. She and colleagues analyzed the results of a three-year, Web-based survey and musical test that required participants to identify notes without the help of a reference tone. More than 2,200 people completed the 20-minute test.
"We noticed that pitch-naming ability was roughly an all-or-nothing phenomenon," she said.
That lead researchers to conclude that one gene, or perhaps a few, may be behind this talent.
Gitschier said those with perfect pitch were able to correctly identify both piano tones and pure computer-generated tones that were devoid of the distinctive sounds of any musical instrument.
She said people with perfect pitch were able to pick out the pure tones with ease. And they also tended to have had early musical training -- before the age of 7.
"We think it probably takes the two things," she said.
They also found that perfect pitch tends to deteriorate with age.
"As people get older, their perception goes sharp. If a note C is played, and they're 15, they will say it's a C. But if they're 50, they might say it's a C sharp."
"This can be very disconcerting for them," Gitschier said.
The most commonly misidentified note, based on the study, is a G sharp. That may be because G sharp is overshadowed by A, its neighbor on the scale, they said. A is often used by orchestras in the West as a tuning reference.
Gitschier said she and her colleagues were focusing on identifying the gene responsible for perfect pitch, which will involve gene mapping. Then they will try to figure out what is different in people with absolute pitch.
"We'll have to play it by ear, so to speak," she said.