《礼记·乐记》
所以喝酒吃饭，是为了皆大欢喜，增进友谊。乐是用来表现德行的，礼是用来制止越轨行为的。
故酒食者所以合欢也；乐者所以象德也；礼者所以缀淫也。
So eating and drinking is about making everyone happy and improving friendship. Music is used to show virtue and rituals are used to stop misbehavior.