Confucius said: “It was only after I returned to Lu from Wei that the music was reformed and the court songs and sacrificial hymns put in the proper order.”
Confucius is probably referring to the Book of Songs (詩經/shījīng), the oldest surviving collection of Chinese poetry and one of the “Five Classics” that became required reading for Chinese students for over 2,000 years.
As his comment suggests, Confucius may have had a hand in editing the volume, but it is highly unlikely that he did the donkey work of slimming down the original collection that reportedly comprised over 3,000 poems and folk songs to just 305 as was (and perhaps still is in some quarters) widely believed.
More likely, he simply gave the Book of Songs his Confucian gold seal of approval and probably did the same for the other four classics – the Book of Documents (尚書/shàngshū), the Book of Rites (禮記/lǐjì), the Book of Changes (易經/yìjīng), and the Spring and Autumn Annals (春秋/chūnqiū) – which he also reputedly edited.
Whatever the actual truth, the association of the Five Classics with Confucius certainly didn’t do them any harm at all, enabling them to survive for over two millennia and play an instrumental role in shaping Chinese history, politics, and culture.
By the same token, Confucius’s association with the Five Classics didn’t do him any harm either, cementing his position as China’s leading philosopher, scholar, and thinker and putting him head and shoulders above his competitors.
Talk about a win-win situation….