Figure 3. Three melodies in musical notation (left) and their corresponding fundamental frequency contours (right).

Melodies B and C are identical to Melody A, except for one changed tone (indicated by red arrows in both the musical notation and the pitch traces). Melodies A and B have the same contour (up, down, up, down, down, down), whereas Melody C has a different contour (up, down, up, up, down, down). The associated sound files illustrate that Melody C (Sound S9) is generally more easily distinguished from Melody A (Sound S7) because of this contour change, whereas Melody B (Sound S8) sounds more similar to Melody A because it has the same contour.