Chinese bells had, by the fifth century b.c., evolved over 800 years, and were sophisticated musical instruments. This is called a yung-cheng, representing the quintessential basic bell type found in high-ranking late Chou tombs. Unlike the po-cheng type shown here, it has an arch-shaped bottom, straight sides, cylindrical bosses, and a columnar shank (yung) with a loop suspension device that causes the bell to tilt toward the player rather than straight up and down. This permitted greater accuracy in striking than with vertically suspended bells--an important feature since yung-cheng bells can emit two notes depending on whether they are struck in the center or midway to the side. The symmetrical group of bosses on each bell probably served to diminish the non-harmonic overtones emitted by the upper part of the bell, thereby emphasizing the fundamental notes.