Cai Zhengren is a Kunqu Opera master, also an actor and director. He's widely recognized as a key figure in preserving the art form. A performer for over six decades, he continues to rehearse at the age of 80. 

Kunqu Opera was a common source of entertainment in China for hundreds of years. It's known for its elegance, dynamic structure and literary appeal. 

In 1930, Peking Opera artist Mei Lanfang took the opera to an international audience in New York. It was met with enthusiasm and acclaim. 

Some seven decades later, Kunqu Opera was listed as a UNESCO intangible cultural heritage. The art form dates as far back as the 14th century in the city of Kunshan near Suzhou, eastern China. It's one of the oldest forms of Chinese opera still performed today. 

But the road to recognition wasn't a smooth one. 

Kunqu began seeing a gradual decline from the 18th century. Of 400 arias, only a few dozen are still performed today. 

"Mr. Cai told us this was both good news and bad news. The good news was that it would bring stimulus. We'd no longer have to borrow money for talent fees. The bad news is we've officially become a legacy," said Zhang Jun, a Kunqu Opera artist, also a student of Cai.

For Zhang, innovation is the key. 

"It's not about breaking up tradition and reshaping the future. It's about respecting the art form and discovering how it has affected and moved an audience for hundreds of years. Art must have mystery, and one needs to uncover it," Zhang said. 

One of Zhang's notable performances is "I, Hamlet," based on a Shakespearean play re-imagined using the classical techniques of Kunqu – a blend of Chinese and Western art forms. In 2011, he was named a UNESCO Artist for Peace for his work in promoting Kunqu Opera among the youth. 

And it seems such efforts pay off. 

Cai Leyi is Cai Zhengren's granddaughter. The 14-year-old says she fell in love with the art form at a young age. 

"The Kunqu singing style is beautiful. The gestures and lyrics are also beautiful," said Cai Leyi. 

For all stage performers, practice is constant and crucial. 

"You have to practice to inherit the art and keep it. You need to master the basics. Only then can you boldly proceed to innovate," said Cai Zhengren.

Since its UNESCO listing, Kunqu Opera has been regaining lost ground, with a growing number of young faces joining in as students and spectators.