During the Warring States Period (475-221BC),the King of the State of Qi was very keen on listening to a traditional musical instrument called Yu ensembles. He used to require 300 Yu players to form a grand music together thus to express his generosity. These musicians could get rather handson payment through playing for the ruler. A man named Nanguo (南郭) learned about that and he wanted badly to become a member of the band due to the big money,even though he was not good at playing the instrument at all. Things went on very smoothly just as Nanguo planed. He successfully got a positon in the Yu band. Whenever the band played for the king,Nanguo just stood in the line,pretending that he was playing with his home heart and soul. However, not even one person paid attention to his fake playing.
Good times don't last long. Several years later, the old king passed away,his son took office,who also enjoyed the beautiful music played on the Yu. However,contrary to his father,he preferred solos to choir so that he was able to appreciate the very essence of the music quitely. Therefore,he commanded the musicians to come forward and play the Yu one by one for him. Nanguo was frightened to death as soon as he hearing the news,he had no choice but to package hastily and run out of the palace. Afterwards,the idiom "Be there just to make up the number" is used to sneer at someone who disguises himselves as a profession in a certain field but is a layman indeed.