Positive affect and structural unity in chord transitions

A model of positive affect associated with the transitions between two chords is presented. It is shown that the transitions perceived to be the strongest are those that involve note diversity and exhibit the greatest structural unity. Unity emerges from two sources: shared features between the chords, and stepwise transitions between the notes of the chords. The degree of unity can be assessed by measuring the activation boost; i.e., the degree to which the units encoding the first chord are maintained while the units encoding the second chord fire. Results are presented showing that the two most powerful transitions, the authentic and plagal cadences, obtain the largest activation boost in the model. Further results are offered showing the effects of resonance between units encoding the chords and the units encoding their respective notes. Finally, a possible role for expectation-related effects within the structural model are discussed.