"Do you hear the people sing", a number from the record-breaking musical Les Miserables, could be heard across Hong Kong on Sunday as two million people marched to demand the city's top official resign over a controversial extradition bill.
The song has become a protest anthem since it was released in 1980 as part of the Les Miserables musical written by Alain Boublil and Claude-Michel Schönberg, based on Victor Hugo's novel of the same name.
Considered one of the greatest novels of the 19th century, Hugo's Les Miserables depicts the life and struggles of working-class French people culminating in a student uprising which ends tragically.
Sung twice during the musical, "Do you hear the people sing" is a call to revolution. The chorus goes:
"Do you hear the people sing?
Singing the songs of angry men?
It is the music of a people
Who will not be slaves again!"
The English lyrics were penned by Herbert Kretzmer.
Protesters in the US state of Wisconsin sung it in 2011, as did activists during Ukraine's Euromaidan movement and Istanbul's Gezi Park protests, both in 2013.
The song also became the unofficial anthem during the Occupy Hong Kong movement of 2014. Recent protests in the semi-autonomous Chinese city over the controversial proposal to extradite people, including foreigners, to the mainland, have seen it sung again with footage widely shared on social media.
The video in the player above was filmed on Sunday when two million Hongkongers flocked to the street to demand the resignation of Carrie Lam, the city's chief executive, despite the official having caved to protesters the day before and shelved the contentious bill.
The Economist magazine reported that the protest song has been censored on the Chinese mainland, with QQ Music, one of the country's most popular streaming service, removing it from its platform.