Relationship between the acoustic characteristics and structural geometry of the tujia dongdongkui

To assess pitch consistency among Tujia dongdongkui sharing a common tuning target, we measured eight geometric parameters and the frequencies of Do, Re, Mi and Sol in ten bamboo instruments, using C5 (523.3 Hz), D5 (587.3 Hz), E5 (659.3 Hz) and G5 (784.0 Hz) as references, and reanalysed two independent recordings per instrument with a common procedure. From Do to Sol, the between-instrument coefficient of variation increased from 9.63% to 13.00%, while mean absolute reference deviation increased from 124.6 to 174.0 cents. Mean symmetric relative frequency differences between recordings ranged from 0.67% to 1.42%, and the increasing between-instrument dispersion from Do to Sol was retained when A, B or mean A/B frequencies were used. The mean Do–Sol interval based on mean A/B frequencies was 741.0 cents, exceeding the 700-cent reference. Length parameters L1–L4 covaried strongly, and none of 32 geometry–pitch associations met the multiple-testing-adjusted significance threshold. Controlled passive-bore calculations for instrument 5 showed that moving the proximal tonehole coordinate L4 by ±2 mm primarily shifted the input-impedance peak for the Sol fingering; peak shifts for the other three fingerings did not exceed 0.50 Hz. The study separates between-instrument variation, repeated-playing differences and within-instrument interval variation, and combines single-dimension perturbations with measurements to identify a direction for physical validation in manufacturing-consistency assessment.