Mechanisms of absolute pitch: II. Pitch shift and perfect touch

The previous article in this series reviewed the historical and modern academic literature concerning the distinctive characteristics of individual musical notes and keys. It stressed Bachem’s definition of tone chroma (TC) as the quality that allows notes/keys to be identified instantly and accurately by musicians possessing the type of absolute pitch (AP) that Bachem described as genuine. TC qualities were shown to vary in the same systematic manner as the second-order acoustical beats predicted to accumulate during the tuning of instruments to equal temperament. This article offers further evidence for the connection between TC and acoustical sensitivity, as indicated by an examination of paracusis musicalis (PM), the shifting of the pitch sense with age to a level sharper or flatter than its original level. It is also noted that AP judgments have been shown to be based on kinaesthetic and tactile sensations, which perform the same cueing functions as auditory TC, and that types of AP judgment may, therefore, exist not typically identified as absolute: for example, an absolute or perfect touch capacity observed in keyboard players. Evidence of this capacity supports the theory of instrument-specific AP.