Gulum is an example of

The Gulum (also known as gurmi) is a traditional two-stringed plucked lute from Northern Nigeria, used primarily among the Hausa people. Because it produces sound through the vibration of stretched strings, it is classified as a chordophone in the Hornbostel-Sachs system of instrument classification.

The Hornbostel-Sachs system categorises instruments into four main families:

• Chordophones produce sound from vibrating strings (e.g., guitar, violin, gulum).
• Membranophones produce sound from a vibrating stretched membrane or skin (e.g., drums such as the dundun or bata).
• Aerophones produce sound from vibrating air (e.g., flute, trumpet, algaita).
• Idiophones produce sound from the vibration of the instrument's own body (e.g., shekere, agogo bells).

Since the gulum uses plucked strings to generate its sound, it falls firmly in the chordophone category.