The Sound of the ‘Kiruncong’ (Bidayuh Bamboo Music Instrument)

Abstract

The kiruncong is a traditional bamboo idiophone of the Bidayuh community in Sarawak, Malaysia, whose acoustic characteristics have received limited scientific investigation. This study examined the frequency spectra, pitch characteristics, and rhythmic function of a single Kiruncong instrument set using Fast Fourier Transform (FFT) and time-frequency analysis (TFA). The six bamboo tubes produced fundamental frequencies of 199, 396, 391, 408, 463, and 507 Hz, corresponding approximately to G3, G4, G4, A♭4, B♭4, and B4. For Tubes 2 to 6, the measured fundamental frequencies were consistent with the perceived pitches. However, Tube 1 exhibited an anomalous pitch perception, with listeners identifying C4 despite a measured fundamental of G3. Since the measured partials did not form the harmonic series required for the classical missing fundamental phenomenon, the perceived pitch is likely influenced by psychoacoustic factors such as inharmonic partials, resonance, transient characteristics, and spectral properties. The results show that the Kiruncong produces complex inharmonic spectra in which the fundamental frequency, partials, dominant spectral peaks, and perceived pitch are distinct acoustic attributes. Rhythmic analysis also revealed interlocking performance patterns characteristic of Southeast Asian traditional music. These findings provide baseline acoustic data that support future ethnomusicological research and the preservation of Bidayuh musical heritage.