此唱彼和

fù jìn méi yǒu dí jūn de shí hou bù duì jiù chàng qǐ gē cǐ chàng bǐ hè

附近没有敌军的时候，部队就唱起歌，此唱彼和。

When no enemy troops were near, whole companies would sing and others would answer the part of a song where a soloist is joined by a group of singers.