An experiment was performed in which subjects had to judge whether the pitch of two sequential sounds went up or down. The sounds were harmonic two-tone complexes. They were constructed in such a way that the frequency of one harmonic remained fixed, the frequency of the other went up or down, and the missing fundamental moved in the opposite direction. Results show that for partials of low harmonic order subjects tend to follow the frequency of the moving partial (analytic pitch perception). For partials of order 6 or higher, about half the observer population retains the analytic mode, whereas the other half switches to a synthetic or holistic mode of perception in which the perceived pitch follows the missing fundamental. The findings ar...