Musical pitch identification by absolute pitch possessors.

Musical pitch identification was investigated in two experiments in which absolute pitch (AP) possessors and nonpossessors categorized tones presented in isolation into predetermined pitch classes. Stimuli consisted of 60 different tones per octave (at intervals of 20 cents). The experiments were designed to minimize the possibility that subjects could use strategies other than AP in perfi~rming the task. The results clearly differentiated AP possessors from nonpossessors in accurac.v and speed of responding. Those subjects who had AP could categorize the tones quite consistently by using musical qualities of the tones (tone chroma). However, they did not respond uniformly to all stimuli; they responded more accurately and quickly to some musically important tones in a C-major mode (C, E, or G). On the other hand, those who had no AP showed almost random response patterns. In the absence of a tonal context, they could not use tone chroma, but only tone height. It is argued that tone chroma should be defined as the musical characteristics of tones in a tonal context, and that AP possessors are unique in that they can perceive it absolutely in the absence of any musical context. Although AP was believed to be very rare, it was proved here that a phenomenally large proportion of the subjects tested had AP. The correlation was observed between AP possession and early musical training that started at the age of 3 to 5.