Meaning of the Idiom
si mian chu ge（hearing the Chu songs on four sides）
At the end of the Qin Dynasty(221-206 B.C.) the State of Chu and the State of Han fought for control for the country.
Xiang Yu, the king of Chu, was besieged at a place called Gaixia by the Han army led by Liu Bang. Xiang Yu was in a desperate situation, with little food and only a few soldiers.
At night, the surrounding Han troops started to sing Chu folk songs. Xiang Yu was very surprised at this, and said:” Has Liu Bang occupied the whole of Chu? How can he have drafted so many Chu people into his army?” Then he fled together with the remainder of his forces.
This idiom is used metaphorically to mean to be in a helpless and critical situation, surrounded by the enemy on all sides.
sì miàn chǔ gē，指四面八方皆响起楚地的山歌；比喻四面受敌，孤立无援。