Key membership and implied harmony in Western tonal music: developmental perspectives.

We investigated the role of key membership and implied harmony in adults' and children's perception of tone sequences. Listeners were evaluated on their ability to detect three types of changes in one note of a well-structured Western tonal melody. In one change (out-of-key) the new note was not in the basis key, in another (out-of-harmony) it was in the key but not in the implied harmony, and in the third (within-harmony) it was in both the key and the implied harmony. Adults and 7-year-olds performed better on the out-of-key and out-of-harmony changes than on the within-harmony change, reflecting their implicit knowledge of key membership and implied harmony. Five-year-olds performed better on the out-of-key change than on the other two changes, reflecting the influence of key membership but not implied harmony. We consider the developmental precedence of key membership over implied harmony in the context of cross-cultural and theoretical perspectives.