Core systems of music perception.

Human musicality is supported by two distinct systems of representation: one for tonal perception, which contextualizes pitch input in reference to a hierarchy of tones; and one for metrical perception, which contextualizes temporal input in reference to a hierarchy of rhythmic groupings. Growing evidence suggests that the two systems are universal, automatic, encapsulated, and relatively early-developing. But like speech perception, and unlike several other perceptual systems, they appear to be uniquely human. The systems of tonal and metrical perception form a foundational structure for musicality that, when combined with the processing of other acoustical information (e.g., timbre or auditory scenes), and applied in conjunction with other cognitive domains, yields a human psychology of music.