The Ruan is also known as the moon guitar, and comes in a variety of different sizes and pitches. It is fitted with four strings and frets. Its soundboard is wooden. Its appearance is much later in Chinese history. Ruan (moon-shaped short-necked lute) is a Chinese fretted instrument dating back to 140-87 B.C. The name is a shortened form of Ruan Xian, a musician and one of the "seven Sages of Bamboo Grove" of the 3rd century (the Six Dynasties). Pictorial evidence, excavated from a tomb of his time in Nanjing, depicting Ruan Xian's performance of this instrument, confirms that its construction was roughly the same as that of today. Later Ruan was once termed as qin pipa (dating to the Qin dynasty between 221-207 BC) or yueqin (moon-shaped short-necked lute).