What is Absolute Pitch (Perfect Pitch)?
Absolute Pitch, commonly referred to as Perfect Pitch, is an intriguing behavioral trait involved in music perception and is defined as the ability to recognize the pitch of a musical tone without an external reference pitch. To be considered a Perfect Pitch possessor, an individual must have the ability to identify pitches accurately and instantaneously.
Main Objective
Our primary goal is to identify the genes that are involved in the development of Perfect Pitch. This study will allow us to better understand the interplay of genetics and musical training in the development of this behavioral trait. These findings may also be applicable to other traits, such as language ability.
The goals of this website are to inform the public about the University of California Study of the Genetics of Absolute Pitch and to recruit individuals to take part in this study. This study is being conducted by the laboratories of Dr. Jane Gitschier at the University of California, San Francisco and Dr. Nelson Freimer at the University of California, Los Angeles. The study has been approved by the UCSF Committee on Human Research. All information collected on individual participants will be kept confidential.
How To Participate In The UC Genetics of Absolute Pitch Study
Take our auditory test and find out if you qualify as an Absolute Pitch Possessor for the UC Genetics of Absolute Pitch Study!
You can start by clicking on GO! at the bottom of this page. First you will be asked to complete a survey. If you indicate in the survey that you are willing to participate in the study, we will need an e-mail address or a phone number to contact you for follow-up. If you are willing to participate you will be linked to a page with instructions on how to take the auditory tests for Perfect Pitch. If you choose, you will be informed of your score and how it compares to the score of the group of Perfect Pitch possessors used as the standard in this study.
If you have indicated your willingness to participate, you may be contacted by e-mail or telephone in order to conduct a brief interview on your family history of Perfect Pitch, and to arrange for a sample of blood (equivalent to two teaspoons) to be taken for our DNA studies. Participation in the study is dependent on your giving consent and your confidentiality is maintained.
General Findings From the UC Genetics of Absolute Pitch Study
Our study suggests that a genetic predisposition for Perfect Pitch and musical training are both important for the development of Perfect Pitch.
A large survey was conducted to assess the role of musical training in the development of Perfect Pitch and to evaluate whether this trait aggregates in families. This survey also served as a springboard for testing individuals for Perfect Pitch abilities by a simple auditory test.
To measure of Absolute Pitch ability, we designed an auditory tone test to objectively assess the pitch discrimination abilities of our study participants. Our auditory tone test consists of two types of tests. The first test consists of 40 pure tones. The second test consists of 40 piano tones. The tests are broken into 4 blocks containing 10 trials. In each trial, a tone plays for 1 second, followed by a silent interval of 3 seconds. Participants record their guesses in the 3 second intervals.
From our initial testing of a mixed population of self-reported absolute pitch and non-absolute pitch musicians, we were able to determine the distribution and mean scores on both the pure tone and piano tone tests. From these distributions and mean scores, we developed five categories of Absolute Pitch ability (AP-1 through AP-5), based on how far a subject's scores vary above and below these mean scores. A scatter plot of the scores of our initial study participants is shown below:
Scatter plot of pure-tone and piano-tone scores of a combined sample of self-reported Absolute Pitch (AP) possessors and self-reported non-AP possessors, examined with the auditory tone tests for Absolute Pitch. The maximum score obtainable for pure tones and piano tones was 36. AP status was assigned to subjects based on their combined pure tone and piano tone scores on the auditory tone test. The vertical dashed line indicates the mean pure-tone score +2 standard errors (SE); the vertical solid line indicates the mean pure-tone score +3 SE. The horizontal solid line indicates the mean piano-tone score+3 SE. (from S. Baharloo, P.A. Johnston, S.K. Service, J. Gitschier, and N.B. Freimer, 1998. Absolute Pitch: An Approach for Identification of Genetic and Nongenetic Components. American Journal of Human Genetics 62, 224-231.)
For the UC Genetics of Absolute Pitch Study, we define absolute pitch possessors to be those participants whose scores fall into the AP-1 category, 3 standard deviations above both the mean pure tone score (solid black vertical line on graph) and mean piano tone score (dotted horizontal line on graph).
Based on the data collected from the surveys and the auditory tests, we found that most individuals with Perfect Pitch began formal musical training before age 6. This supports the hypothesis that early musical training may be necessary for the development of Perfect Pitch. However, early musical training alone is not sufficient for one to develop Perfect Pitch, as most individuals with musical training initiated before age 6 did not report that they possessed Perfect Pitch. We also observed that Perfect Pitch aggregates in families, indicating a role for genetic components in the development of Perfect Pitch. Indeed we found that a sibling (with early musical training) of a Perfect Pitch possessor is as much as 15 times more likely to possess Perfect Pitch than is another individual with early musical training but with no family history of Perfect Pitch. (See the PRESS link of this website for more information on this study.)
Current Status Of the UC Genetics of Absolute Pitch Study
To find genes responsible for the predisposition for developing Perfect Pitch, we must identify individuals who fulfill a stringent definition of Perfect Pitch via our auditory tone test. To fully participate in the genetic study, these individuals must also be willing to provide us with a DNA sample and must have additional family members who are also willing to provide us with a DNA sample. These DNA samples are used in gene mapping studies to determine linkage between specific genetic markers on our chromosomes and the Perfect Pitch trait. By this process we hope to home in on the gene or genes that influence the development of Perfect Pitch. We anticipate that over 100 families with multiple Perfect Pitch possessors will be needed for the successful completion of this study.
