Nüshu is one of the very few scripts created by a woman or women, and used exclusively by women (largely in secret) for specific purposes and using specific materials. It has also, in some important respects, become extinct, but for equally important reasons is enjoying something of a revival — of interest, if not of daily use. Nüshu (the word means “women’s script”), was adapted from Chinese characters and was used exclusively among women in Jiangyong County in Hunan province of southern China, its use not being known outside that community until 1933.

It is not known when or how Nüshu came into being — certainly no earlier than 900 — but it seems to have reached its peak during the latter part of the Qing Dynasty (1644–1911).

Unlike Chinese, Nüshu writers valued characters written with very fine, almost threadlike, lines as a mark of fine penmanship. The writing was sometimes modified to fit an embroidery pattern, or fit the individual panels of a fan: concealment was part of its very identity.

This fact underlies almost every aspect of Nüshu — not just because women were not permitted to learn to read and write, but because Nüshu was used to capture and communicate aspects of women’s lives that were also personal, private, or secret. It is little exaggeration to say that Nüshu represents, both metaphorically and literally, the world of women at a time and in a place when that world was largely invisible to men, and was neither understood nor respected.

I would never have grasped the depth and importance of Nüshu had it not been for the fact that one of my colleagues, Catherine Morgan, was retiring to Florida and renovating a house. She asked if I would make an endangered alphabet carving for the foyer, and after some discussion we settled on a Nüshu proverb I found online: “Beside a well, one does not thirst. Beside a sister, one does not despair.”

This raised a series of questions. Who were these women? What must their life have been like, to need a secret language? And what do you say or write that you can only say in secret? The questions are answered, or at least answers are suggested, by Tan Dun’s “Nu Shu: The Secret Songs of Women,” which I saw in performance by the Philadelphia Orchestra at the Saratoga Performing Arts Center.

Tan Dun, who scored the movie Crouching Tiger, Hidden Dragon, went back to a remote village in his native province of Hunan, recorded over 200 hours of audio and video, and created a multi-media work for orchestra, recorded voices and projected images.

The work consisted of thirteen movements: Secret Fan; Mother’s Song; Dressing for the Wedding; Cry-Singing for Marriage; Nu Shu Village; Longing for Her Sister; A Road Without End; Forever Sisters; Daughter’s River; Grandma’s Echo; The Book of Tears; Soul Bridge; and Living in the Dream.

The featured solo instrument was the harp; the instrumentation was predominantly strings, flute, oboe, and percussion, with additional handmade sound effects: water trickling into a bowl, the string players’ bows rapping on their instruments to imitate the snapping of fans.

The music was by turns dramatic, plaintive, reflective, melancholy and grief-stricken, but it was the video images of the (mostly elderly) women singing in Nüshu and the circumstances of their singing that changed everything.

“Dressing for the Wedding,” for example, sounded like a joyful title until it became clear that the wedding would have been arranged, the daughter no more than fifteen years old, and the wedding itself might be the last time the mother and daughter might ever see each other.

Nowhere was this unsettling combination of celebration and grief more evident than in the fourth movement, “Cry-Singing for Marriage.” In this culture the wedding tradition, according to Tan Dun’s program notes, featured three days of constant crying, stylized into song, while mother and daughter together wove a scarf to be worn at the wedding. The resulting tear-soaked scarf would serve as a link — perhaps the only tangible link — between mother and daughter.

This was followed by the cheerfulness-in-daily-life humor of “Nu Shu Village,” but the real meaning of Nüshu was already clear: it was developed to express emotions that were inconvenient or even unacceptable to the orderly regulation of human life, and as such these songs represented an entire panorama of concealed emotion. Mothers losing daughters, daughters losing mothers, sisters losing each other — a social web so torn, so desperate it needed a secret language to bear such emotional weight.

The apparently tranquil, even transcendent “Soul Bridge,” which showed a young woman walking thoughtfully across an ornate bridge, had a sadder undercurrent: this was a bridge where she walked to remember her mother, who might be dead or simply not seen for decades.

The final movement, celebrating the working community of women, provided a cheerful ending, but this in turn implied how much that community was needed when those women were routinely separated, sundered, left devastated and facing despair.

Yang Huanyi, the last person proficient in Nüshu, died in 2004, at the age of 98.

In 2002, Nüshu was added to the Chinese National Register of Documentary Heritage, and four years later the State Council listed Nüshu as a national intangible cultural heritage. A Nüshu museum was built in Puwei Island, Jiangyong County, in May 2007. According to Yang Cheng, Director of the Jiangyong Publicity Department, “The special Nüshu culture is the crystallization of the collective wisdom of women whose spiritual pursuits of intelligence, sense of self-respect, self-improvement and innovation have allowed various civilizations in the world to blossom with radiant splendour. And the protection of this national culture requires not only attention from academics, artists and officials, but also, more importantly, the cultural awareness of local people.”

According to UNESCO, “local governments are currently commissioning Nüshu specialists (researchers and authors) to prepare easy-to-understand manuals to explain the historical background, values and basic elements of Nüshu culture — stressing its significance and the need for its preservation. This content will be included in primary and secondary elective courses, to popularize the unique women’s script.”

A Japanese equivalent women’s script named Kana was used by women from the tenth century to the mid-twentieth to write literature (including what some regard as the world’s first novel, The Tale of Genji), arrange secret assignations and express themselves freely within the confines of court life. A calligrapher named Kaoru Akagawa is currently trying to revive it.