The army has always been known for its prohibitions and strict discipline, and in ancient wars, there was a special order to "beat the drum and march forward, and the gold should be withdrawn". This statement first appeared in "Xunzi Han Bing", which has a description of "advancing when you hear the sound of drums, and retreating when you hear the sound of gold", which means that the order to beat the drum means to attack, and the order to sound gold means to retreat. Some people think that the "jin" in "Ming Jin Collects Soldiers" is a gong, but it should actually be "钲" (zhēng), an ancient bronze instrument that is long and narrow in the shape of a bell, with an upward mouth, and a crisp, loud and penetrating sound when struck, which can travel long distances. On the battlefield, the soldier can clearly hear this voice in order to command. It is recorded in "Shuowen Jie Zi": "The cymbal, like a bell, is up and down in the handle." "Mingjin" originally referred to the striking of this instrument for retreat, and may have been replaced by tools such as gongs. 
The cymbal, shaped like a bell, but narrower and longer than the bell, has a handle above it and can be hung. In ancient warfare, once the cymbal was struck, it meant that the battle was over and both sides retreated. The ancients "beat the drum to march and sing the gold to collect the army" contains a certain scientific principle: the drum is made of leather, and the sound is rich and shocking when struck, which can play a role in motivating;The cymbal's sound is crisp, penetrating, and has a long travel distance, making it easy for soldiers to hear the retreat signal clearly. 
The cymbal, is a kind of percussion instrument in ancient times, also known as "Ding Ning", its body resembles an ancient bell, but there is no bell mouth, but it is a tile shape. The drum is short and broad, with a deep concave arc at the mouth, sharp on both sides, and a long handle to hold, which makes a melodious sound like a morning bell and a dusk drum, and is the best of the marching instruments. Although its appearance is not good, it can inspire the fighting spirit of thousands of troops. 
The most important feature of cymbals is that they communicate with the inner cavity of the cymbals. Archaeological findings show that most of the cymbals are made by plant sounds, that is, the handle is inserted into the wooden seat and struck to make a sound. This is also confirmed by the fact that the cymbals had their mouths facing upwards and were inserted into the wooden pedestals with their handles inserted into the wooden pedestals, and that some of the excavated cymbals could only read their inscriptions with their mouths facing upwards. "Commentary on the Interpretation of Words" says: "The cymbal is like a bell and different from the bell, the bracelet and the bell are like a bell, and there is a handle for the tongue to have a sound." The cymbal has no tongue handle, and the handle is half on the top and half on the lower ......"The cymbal can also be suspended, and the handle of the cymbal unearthed has a perforation or square or circle, and the rope can be worn in it to hang and percussion, such as the copper cymbal unearthed from the Han tomb of Luozhuang and the "Ran cymbal" used by Wu Wang Shoumeng.