Bach’s organ writing can produce Shepard-like pitch ambiguity in listeners

Evidence

A musical example relating to the Shepard tone effect in which some pitch ambiguity is perceived by some listeners can be found in the pedal line starting at bar 31 of the Fantasia in G Minor (BWV 542) for organ by J. S. Bach (consider tracks 70–72 on the accompanying CD). These bars are reproduced in Figure 5.20 as an organ score in which the lower of the three staves is played on the pedals, while the upper two staves are played with the left and right hands. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1644

Categorization

• SEED: Angle: how Baroque organ pedal writing accidentally anticipates a 1960s psychoacoustic illusion — a short essay on illusionism in early music.
• XREF: Links a listening-experience goal with a reproducible listening test using the accompaniment CD. — connects to: Shepard-tone ambiguity arises in real music such as Bach’s organ works — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1645; Bach’s organ pedal leaps create perceptual pitch ambiguity for listeners.; Organists shape timbre by selectively reinforcing harmonics of one series — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1526 (+17 more)

Broader Connections

• Shepard-tone ambiguity arises in real music such as Bach’s organ works #corroborates (1.00) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1645
• Bach’s organ pedal leaps create perceptual pitch ambiguity for listeners. #expands (1.00)
• Adding harmonic-series members of an unsounded note creates perceptual ambiguity about pitch location. #expands (0.90) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1649
• Organ resultant stops create the sensation of pitches below any note actually sounding #expands (0.90) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1650
• Organists shape timbre by selectively reinforcing harmonics of one series #complicates (0.85) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1526
• Changing organ reed stops can create an illusory continuously descending pitch line #complicates (0.85) — David Howard, Jamie Angus, coustics and Psychoacoustics, 3022
• Shepard tones are not perceptually identical across the octave. #complicates (0.80)
• Organ builders exploit missing-fundamental perception to create bass notes no pipe actually sounds #complicates (0.80)
• A Shepard tone creates an endlessly ascending pitch while staying within one octave #complicates (0.80)
• Endlessly accelerating beat rhythms are Shepard tones shifted down in frequency. #complicates (0.80)
• High-pitched soprano singing sacrifices intelligibility for audibility #complicates (0.75)
• Pipe organ stops can reinforce non-octave harmonics to reshape timbre #complicates (0.75)
• Organ pipes’ timbre arises from resonances cooperating with edge tone #complicates (0.75)
• Listeners stream interleaved tones by pitch rather than by ear of delivery #complicates (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1620
• Pitch’s musical expressiveness may rest on detecting pitch differences, not complex interval patterns #complicates (0.75)