How does the bow of a huqin produce sound on its two strings?

In the context of Chinese music, the bow of a huqin—a group of two-stringed Chinese fiddles—produces sound through friction generated by rosined horsehair.12

Unlike many Western stringed instruments where the bow is separate, the bow of a huqin is typically integrated into the instrument. The horsehair of the bow passes between the two strings, while the arched wooden stick remains on the outside, meaning the bow cannot be detached from the instrument.13

During performance, the player holds the instrument vertically on their lap or thigh. The tension of the bow's horsehair is controlled directly by the pressure of the performer's right hand. By drawing the bow horizontally across the strings, the friction causes the strings to vibrate, and this vibration is then amplified by the instrument's resonator, which is often covered by a snakeskin membrane. This unique bowing configuration allows for a wide range of expressive techniques, including subtle contrasts in bowing strength, glissandos, and vibratos.1435