Bianzhong of Marquis Yi of Zeng

The set of 65 bronze bells can accurately play a full 12-tone chromatic scale across five octaves. This sophisticated tuning was completely unknown in China during the 5th century BC before its discovery.

Each bell features an almond-shaped (almond-leaf) cross-section instead of a perfectly round one. Because of this unique design, striking the bell in the center produces one pitch, while striking it on the side produces a completely different pitch.

The massive set of bells was buried in the tomb of Marquis Yi of Zeng, a regional ruler in the Warring States period. He was laid to rest in what is now Hubei Province, China, around 433 BC.

The bells were discovered in 1978 inside a massive, waterlogged tomb in Suixian (modern-day Suizhou), Hubei Province. The waterlogged environment helped preserve the massive wooden frame holding the bells completely intact.