Þruma

Þruma is a rare and ancient vocal phenomenon that originates from the gamelan music of Indonesia. It is characterized by a low, droning sound that resonates through the vocal tract, often accompanied by specific vocal techniques and breath control. Þruma is typically performed by experienced gamelan musicians who have mastered the complex vocal and instrumental techniques of this unique musical style.

The creation of ðruma is attributed to the movements of the glottis, the opening between the vocal folds in the larynx, which produces a low pitched humming sound. This sound is further modulated by the shape and size of the vocal tract, determined by the position and tension of the tongue, lips, and jaw. Skilled performers are able to manipulate these articulatory features to produce a wide range of expressive ðruma sounds.

In the context of gamelan music, ðruma is used to create a rich and complex texture of sound, often supporting and elaborating on the melodic lines of the other instruments. It is also used for evocative and atmospheric effect, filling the space and creating a sense of drama or tension. Among gamelan enthusiasts, ðruma is considered an essential element in gamelan performance, requiring mastery and control to produce the desired effects.

Research into the acoustic properties of ðruma has revealed its distinctive characteristics, including its low frequency range and unique waveform shape. Further studies have analyzed the physiological processes involved in producing ðruma, providing insights into the complex interactions between breath control, vocal fold vibration, and the movement of the glottis. The cultural and historical significance of ðruma within Indonesian music traditions has also been studied, highlighting its importance as a key element in the expressive and symbolic world of gamelan music.