A stopped flue pipe’s odd-mode support creates its characteristic chiff at onset

Evidence

The stopped flue supports only the odd modes (see Chapter 4), and, during the onset phase of this particular example, the fifth harmonic sounds first, which is the second overblown mode sounding two octaves and a major third above the fundamental (see Figure 3.3), followed by the fundamental and then the third harmonic, giving a characteristic chiff to the stop. — David Howard, Jamie Angus, coustics and Psychoacoustics, 1474

Categorization

• DEFINE: Explains the mechanism behind ‘chiff’ — the transient sound of organ pipes — as staggered harmonic entry determined by mode structure.
• XREF: connects to: A stopped cylindrical pipe supports only odd-numbered modes — David Howard, Jamie Angus, coustics and Psychoacoustics, 1241