Watch Crowd at Paris Rally Sing John Lennon's "Imagine"

Up to 2 million people and more than 40 world leaders filled the streets of the French capital Sunday to honor the victims of the 'Charlie Hebdo' massacre.

Parisians looked to John Lennon for inspiration in their darkest moment by singing his iconic "Imagine" at Sunday's rally in the French capital.

The rallies of national unity were organized to honor the 17 victims of two terrorist attacks, one on weekly satire magazine Charlie Hebdo. The Paris rally saw up to two million hit the streets, as well as more than 40 world leaders.

In total, 3.7 million people joined public demonstrations across France. 

Watch a video of the crowd singing "Imagine" at the Paris rally below...

Read more Jon Stewart on Paris Attacks: "Comedy Shouldn't be an Act of Courage"