and imperial periods. On 7 November 2003, UNESCO announced that the Chinese guqin was selected as an Intangible World Cultural Heritage. In 2006, guqin was listed in the List of National Non-material Cultural Heritage in China. In 2010, a Song period guqin was sold for $22 million, making it the most expensive musical instrument ever sold. History Legend has it that the qin, the most revered of all Chinese musical instruments, has a history of about 5,000 years, and that the legendary figures of China's pre-history – Fuxi, Shennong and Huang Di, the "Yellow Emperor" – were involved in its creation. Nearly all qin books and tablature collections published prior to the twentieth century state this as the actual origins of the qin, although this is now viewed as mythology. It is mentioned in Chinese writings dating back nearly 3,000 years, and examples have been found in tombs from about 2,500 years ago. The exact origins of the qin is still a very much continuing subject of debate over the past few decades. In 1977, a recording of "Flowing Water" (Liu Shui, as performed by Guan Pinghu, one of the best qin players of the 20th century) was chosen to be included in the Voyager Golden Record, a gold-plated LP recording containing music from around the world, which was sent into outer space by NASA on the Voyager 1 and Voyager 2 spacecraft. It is the second-longest excerpt included on the disc. The reason to select a work played on this specific instrument is because the tonal structure of the instrument, its musical scale, is derived from fundamental physical laws related to vibration and overtones, representing the intellectual capacity of human beings on this subject. In 2003, guqin music was proclaimed as one of the Masterpieces of the Oral and Intangible Heritage of Humanity by UNESCO. Schools, societies and players As with any other musical tradition, there are differences in ideals and interaction between different people. Therefore, there exist different schools and societies which transmit these different ideas and artistic traditions. Historical schools Many qin schools known as qin pai developed over the centuries. Such schools generally formed around areas where qin activity was greatest. Some schools have come and gone, and some have offshoots (such as the Mei'an school, a Zhucheng school offshoot). Often, the school is originated from a single person, such as the Wu school which is