Adding harmonic-series members of an unsounded note creates perceptual ambiguity about pitch location.

Evidence

In bar 32, the left-hand change from E♭to E natural adds a member of the harmonic series (see Figure 3.3) of what would have been the next note (written C3) in the pedal scale had it not risen up the octave. E♭ is not a member of that harmonic series. The case is similar for the D♮ in the right hand in the third bar of the extract with the entry of the left-hand F3 and the left-hand C natural in the fourth bar. These entries of notes which are members of the harmonic series of what would have been the next note in the descending pedal scale had it not jumped up the octave serve to provide the perceived ambiguity in definition as to the exact instant at which the upward leap occurs. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1649

Categorization

• XREF: Connects to the book’s earlier harmonic series machinery (Figure 3.3) and Chapter 3 pitch perception; this is the missing-fundamental logic applied compositionally. — connects to: Higher-order combination tones can be misheard as actual played notes — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1589; Bach’s organ writing can produce Shepard-like pitch ambiguity in listeners — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1644; Missing-fundamental illusions depend on a musical context being established first — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1656