for the first three points 037 (minor triad) for the second three, 047Q (major-minor tetrad) for the third three, and 036Q (half-diminished tetrad) for the last three.

Figure 3a contains the only trial in which chords were identical. Almost all listeners responded “very similar” to this trial. Next in the rank order to mean responses were pairs of major triads (047) with intervals of 5 and 8 semitones between their roots. Surprisingly, the rising fifth (7) was judged more similar than the musically more usual rising fourth (5) (cf. Bharucha and Krumhansl, 1983). Next in line were third relationships (3, 4, 8-but, surprisingly, not 9-semitones). Like fifth relationships, these involve one common tone (for example, the tone 7 is common to 047 and 37Q). The low response at the tritone interval (6) is in line with music theory.