Incremental Process of Musical Key Identification

Pitch set is a primary cue for key perception. However, pitch set alone cannot account for the phenomenon that listeners perceive different keys for melodies that consist of the same pitch set but exhibit different temporal arrangements. Contrary to previous results, a recent study demonstrated that additional cues based on sequence properties (e.g., the augmented fourth, a pitch class in the final position of a melody, etc.) did not contribute to key perception. To explain this phenomenon, we traced how listeners developed a sense of key as melodies (with the same pitch set differing in pitch sequence) unfolded over time. In each melody, listeners identified the key following the presentation of a segment of pitches where the number of tones within a segment increased with successive presentations. Results suggested that listeners gradually established the sense of key. Throughout the progress of melodies, the listeners’ key responses were governed by a set of pitches within a segment provided a given point in time. These findings suggest that key identification is derived from the incremental changes of the pitch set with unfolding of a melody.