Millions took to the streets in Paris Sunday in a march for unity, believed to be the single largest demonstration in France’s history, after the terrorist attack on satirical newspaper Charlie Hebdo and subsequent hostage situation that left 17 dead and a country in mourning.

Though there were countless images both joyful and sad from the rally, one indelible clip uploaded to YouTube this morning shows a portion of the crowd singing along to John Lennon’s seminal anti-violence anthem “Imagine” as the song is played out an apartment window.

Much could be written on thie subject, but we’ll let Lennon’s words speak for themselves.

Imagine there’s no countries
It isn’t hard to do
Nothing to kill or die for
And no religion too
Imagine all the people
Living life in peace…

You may say I’m a dreamer
But I’m not the only one
I hope someday you’ll join us
And the world will be as one