After soliciting musicians at local symphonies and music conservatories to take part in his study on perfect pitch, a UCSF researcher has been deluged by willing Jewish participants from all over the country.

The researcher, graduate student Siamak Baharloo, so far has tested about 100 individuals for their ability to quickly assign musical notes to a variety of simulated tones.

Baharloo specifically seeks Ashkenazi Jews because their gene pool is more homogeneous than other groups, making it easier for researchers to locate the causal gene. The group also exhibits a slightly higher incidence than the general population of perfect pitch, which is developed at an early age through musical training.

Scientists believe that perfect pitch arises during a critical developmental stage of childhood. A person who is biologically wired for perfect pitch will not necessarily develop the trait without musical learning. Baharloo's study is the first of its kind designed to pinpoint a characteristic that is the product of both genetic makeup and environmental influence.

His work first won notice on the pages of the San Francisco Examiner. The Bulletin also ran a story, which subsequently appeared in Jewish newspapers around the country.

The coverage snowballed. The New York Times picked up the story, as well as National Public Radio and several medical trade journals.

"The attention has been good [for the study] because people with perfect pitch are so rare," the researcher said.

"Everybody that I have been in contact with has been so wonderful. They are brave to step forward. Often, you end up with [disease studies] where there are taboos or cultural [stigmas that discourage participation]."

But, "It's a very functional, educated population," he noted of his Jewish participants.

While some of Baharloo's subjects are celebrated musicians, such as violin virtuoso Gil Shaham, most represent a cross-section of society — piano tuners and music teachers, moms and molecular biologists.

Some even ventured here from other parts of the country to take the auditory test and give a blood sample for genetic analysis.

Often, the researcher would be invited to dinner by his subjects, who would while away the evening sharing family trees, historical photos and tales of pre-World War II Europe.

As part of his study, Baharloo is trying to pinpoint a common ancestor of all European-descended Jews with perfect pitch.

Genetic research and historical accounts suggest that the 15th- or 16th-century population of Ashkenazi Jews that actually procreated was comprised of only a few thousand individuals. Among that population, one or two people with perfect pitch may be responsible for all of today's Ashkenazim with the trait, he believes.

Already, Baharloo has tested several unrelated individuals who can trace their ancestry to the same shtetl.

The study is still more than a year from completion. After Baharloo has tested enough people, he will begin the more difficult task of determining whether perfect pitch is caused by one gene or if it's a more complex trait created by a combination of genes.

Individuals of all ethnicities who believe they have perfect pitch are encouraged to contact Baharloo at (415) 476-7860.