The processing of chords in tonal melodic sequences

A model is proposed for the On-Line Harmonic Processing (OLHP) of tonal melodic sequences in which each incoming tone is described in terms of its features Fittingness, compliance with the previous harmony, Uncertainty, ambiguity of a new harmony and, Chord Change, goodness of the connection between previous and new harmony. To test this model in Experiment 1 listeners rated the musical logic of 10-tone sequences presented with an induced segmentation in groups of 3-3-3-1, and following an harmonic progression of I-target-V-I, respectively, with the harmonic functions I, II, III, IV, V, or VI inserted as target fragment. The results support the Chord Change feature of the model. In Experiment 2 these sequences were rated as tone-by-tone increasing fragments, starting from the initial 3 tones up to the complete sequence. The ratings of the incremental sequences supported the findings of the first experiment. The three features in the model explained 46.4 % of the variance in the target ratings, although Uncertainty seemed to have no effect. In a comparison with two other models OLHP model performed best. Finally, an a-posteriori model consisting of Chord Change and a variable quantifying pitch proximity between consecutive tones accounted for a major part of the variance. It is concluded that listeners employ OLHP's features in their representation of the sequences and that both harmony and pitch height are indispensable factors in a model of melody perception