How were ancient instruments classified according to the hornbostelsachs system?

The Hornbostel-Sachs system classifies Musical Instruments into four main categories based on how they produce sound: idiophones (self-sounding instruments like bells), membranophones (instruments that produce sound via vibrating membranes, such as drums), chordophones (string instruments that generate sound through vibrating strings, like violins), and aerophones (instruments that produce sound by vibrating air, such as flutes). Each category can be further subdivided based on specific characteristics, allowing for a comprehensive classification of diverse musical instruments from different cultures. This system provides a structured way to understand and compare instruments across the world.