For members of elite households, painting was a shared language, Zhao Xu reports.

If you are a friend of a powerful art family and own a painting by its patriarch, what would you do? The answer from Xie Boli, a collector living in 14th-century China, produced one of the most prominent and talked-about works in Chinese art history.

The original piece that was in Xie's possession was Groom and Horse by Zhao Mengfu (1254-1322), a crucial figure in the evolution of China's literati painting tradition. Exactly how and when Xie came to own this masterpiece remains unknown to modern-day art historians. But what they do know, from the inscriptions on the complete piece as we see it today, is that the collector approached Zhao Yong, the master's son, in the autumn of 1359 and then his grandson Zhao Lin barely two months later.

On both occasions, Xie asked if another picture of the same theme could be added to the existing one, and his wish was granted both times, resulting in a paint scroll that features, in succession, three pairs of horse and groom, as rendered by three generations of the Zhao family.

The piece kept growing in the ensuing centuries, with nine people who had come into its audience putting down their thoughts in colophons that are attached to it. The last one of them is poet and figure painter Chen Hongshou (1598-1652).

"Instead of mere ink-and-brush skills, the most precious thing that could be transmitted from one man to his posterity is the moral value and the literary tradition in which it is embedded," Chen wrote, probably thinking about himself and his son Chen Zi, who had inherited in his own art the old man's style but not his signature "quirky charm", to use the words of Joseph Scheier-Dolberg, the man behind the ongoing exhibition Learning to Paint in Premodern China at the Metropolitan Museum of Art in New York.

The curator has put on display both the Zhao family painting and an album featuring four painted leaves from Chen Hongshou and seven from his son — they are believed to have been brought together either by a collector or by the son himself.