A video clip of a choir comprising 36 geriatrics singing a popular song titled Adolescents during an online gala to celebrate Lunar New Year in early February went viral and inspired many younger viewers.

These seniors, who are age 75 on average, clad in dress shirts and bowties, won thunderous applause from the audience in the studio after their performance at the gala. Many internet users have also expressed their admiration of the group's spirited display.

"I don't see their silver hair. I only see their ardent affection for life. It is because of such affection that they've been crowned by the brilliant radiance of time," reads a comment by a netizen with the username Sirlin.

The elderly singers, however, aren't just regular senior citizens with a penchant for music.

Formed in 2008, the choir is made up of more than 100 alumni of China's prestigious Tsinghua University. In fact, many of those who took to the stage for the gala show are regarded as the unsung heroes behind China's rapid development over the decades.

For example, choir member Cheng Bushi was a technical adviser for the C919, China's large passenger aircraft, and the deputy chief designer of China's first-generation jet aircraft in the 1970s.

Zhang Lixing and his wife, Zhu Fengrong, both of whom are in their late 70s, majored in nuclear energy at Tsinghua and assumed key roles in a nuclear-testing base in the Xinjiang Uygur autonomous region.

Meanwhile, the choir's founder, Liu Xila, and his wife, Chen Chen, have the honor of being the first couple to return to the country with doctorates from Purdue University in the United States in the 1980s.

Following their return to the country, Liu worked as a professor at Tsinghua while Chen worked in Shanghai Jiao Tong University. Chen was one of the professors who established the PhD program for electrical engineering at SJTU.

Chen, who taught at SJTU for 23 years since 1985, says that many of those assuming key positions in the country's electrical engineering sector today used to be her students.

Music brought the couple together. More than half a century ago, Liu met Chen during his preparations for a solo violin concert.

"Another female schoolmate was supposed to provide the piano accompaniment to my concert, but Chen replaced her because she had better rhythm," he quips.

According to Liu, the choir was formed when he realized that many of his fellow alumni were once members of the Tsinghua art troupe.

"Singing was an excellent way of bringing back the good memories as old songs very easily transported us to the past－an age where supplies were scarce but the spirit of fighting for a better tomorrow was high," says Liu.

Many people heard about the choir and its compelling performances. Over the years, the choir has performed on a variety of high-profile stages, such as programs by provincial television stations and the Shanghai World Expo in 2010.

Besides enabling them to stay in touch, the choir also became a stage for the elderly alumni to fulfill their desire of contributing to society through other means.

"We gradually realized that the choir was not just a mere form of recreation. We saw this as something that we could use to continue contributing to today's society by influencing the young people," says Liu, who was also a professor of civil engineering at SJTU.

"I believe this spirit that we have has remained unchanged for generations, but it's particularly important now as the world faces challenges from the COVID-19 pandemic," he adds.

"We want to encourage the younger generations to continue shouldering responsibilities for the country and the world."

Liu says that the choir practiced the song for only two months after receiving the performance invitation from the online-gala organizer. Due to the pandemic, most of the practice sessions were conducted online.

Another challenge they faced was mastering a modern upbeat song, which is very different from the nostalgic, slower-paced nationalistic tunes that the choir is used to singing.

The lyrics, however, encapsulate the same spirit of doing one's part for the nation.

"The old songs we usually sing have lyrics such as 'going to the places where I am needed the most for the country's development'. In Adolescents, the song talks about 'never giving up' and 'being like fire', which in a way bears the same meaning," he says.

"While they may be songs from different eras, the theme is the same－we must stay committed to the goal of revitalizing this country."