Key Change: Reframing Perfect Pitch
The ability to recognise and label the pitch of a musical note is an important component of musicianship. For most musicians, this is achieved using contextual cues, by identifying the relative distance between the pitches of notes in chords and melodies (relative pitch; RP). Some, however, can additionally identify and label musical pitches in isolation. This skill is known as perfect or absolute pitch (AP), and has been linked to differences in brain structure and function. Although AP is commonly conceptualised as a binary trait, variability in pitch-naming ability has been widely reported, prompting speculation that AP skill lies on a continuum rather than constituting a distinct categorical trait. Expression of this unusual ability is thought to be influenced by heritability, early music training and current practice. However, our understanding of factors shaping its expression is hampered by testing and scoring methods that treat AP as a dichotomous trait. These fail to capture the observed variability in pitch-naming accuracy among musicians, including those who report using both AP and RP strategies to name notes.
Research Questions / Hypotheses
In this study, we aimed to investigate pitch-naming ability using a method that can capture variability in pitch-naming, including those who may use a combination of relative pitch (RP) and absolute pitch (AP) strategies to identify musical pitches. Using this explicit priming paradigm, we expected that we would identify subgroups or phenotypes of pitch-naming ability, beyond the ceiling-floor dichotomy often reported in AP literature. We also aimed to investigate factors associated with these phenotypes, including the musical experience of participants and their families.
In Semester 2 2020, 93 participants signed up to the Key Change website through the REP program. Key Change now has more than 500 participants, with data collection continuing over Summer 2020/2021.
Participants completed the study through the Key Change website, using personal computers and headphones. A subsample (n = 10) participated in a laboratory environment with a provided computer and headphones for validation purposes. Demographic and musical background information was obtained, including questions about the musical experience of family members. All participants were initially tested for AP using a well-established test of pitch naming accuracy, comprising 50 synthesised piano tones. This screening task was used to classify individuals according to previously published AP research methods, and provided a reference point against which to compare performance of the novel priming task. The priming task comprised pairs of synthesised piano tones drawn from the central pitch range C3 (130.81 Hz) – C5 (523.25 Hz). An initial 500 ms “prime” tone was followed by a second “target” (500 ms) to be verbally labelled by participants. No feedback was provided regarding the identity of either prime or target. Following a 3500 ms response interval, an environmental sound without a clear pitch was presented for verbal identification, which served as a distracter item to limit pitch interference between trials. Sounds included vehicle noises, human sounds (e.g. coughing, laughing), animal noises, percussion instruments, tools and other sounds such as breaking glass and gunshots. At the conclusion of the study, participants were asked to invite any family members with musical experience to participate via email, using a unique code that would allow a family's responses to be linked.
A preliminary lab-based study using the priming paradigm revealed phenotypic variability of AP ability, including high-accuracy AP, heterogeneous intermediate performers, and chance-level performers. Some participants were able to use RP strategies to identify target notes in the priming task based on the identity of the prime. As a proof of concept study, this showed that the novel priming task was able to show greater heterogeneity in AP ability than has previously been accessible, which is a key step towards identifying AP phenotypes. In the current web-based study, we will further investigate these phenotypes using taxometric analysis. This statistical method evaluates whether the distribution of AP accuracy should be treated as a continuum or a set of distinct categories.
Our study has shown that consideration of phenotypes is paramount in investigations of AP, highlighting the necessity for robust methodology to ensure that the phenomena revealed are representative of true phenotypic differences. For the first time, we have been able to show how RP strategies can be used to bolster incomplete pitch-naming templates through use of an AP priming paradigm, revealing individual differences within an intermediate-accuracy group. This study represents a considerable step forward in AP research, furthering our understanding of this trait and facilitating future research into its underlying mechanisms. The proof-of-concept study preceding Key Change is currently under review for publication, and its results have previously been presented at the International Conference on Music Perception and Cognition, 2018. The Key Change website was launched in a presentation at the International Symposium on Performance Science, 2019. Results from Key Change will be disseminated in peer-reviewed journals and will form part of Jane Bairnsfather's PhD thesis.