There is a great article about a 9000 year old bone flute that was discovered in the 1980s in China. Pretty interesting stuff. Some of the highlights are:

1. The form of Jiahu flutes: There are five or six holes in bone flutes of the early period; seven holes on most flutes of the middle period; and seven or eight holes in the latest period.
2. The concepts of “scale” (Shu) and “temperament” (Lu) in making the Jiahu bone flute: flutes of each period had some changes in the arrangement of scale and this indicates that our Jiahu ancestors already had certain temperament standards when making different tones.
3. Why the world of musical research is amazed by the accuracy of the tuning system of the Jiahu bone flute number 341:2: The method of hole-drilling and the arrangement of the five-tone scale demonstrate that, at that time, the practice of Chinese music had already entered a completely new realm.
4. The inheritance and selectivity of musical culture: during a continuous period of 1200 years, Jiahu musical production developed from a four-tone scale to a seven-tone scale through successive changes, and from complexity to a high level of simplicity, and this trend bears an important significance to modern musical composition.