Watch Pianist Perform John Lennon's 'Imagine' Outside Paris' Bataclan

Mysterious musician delivers poignant version of Beatle's 1971 classic as mourners gather at site of massacre

As mourners gathered outside Paris' Bataclan venue, an unknown musician set up a piano and delivered a poignant take on John Lennon's "Imagine."

As hundreds of mourners gathered outside Paris' Bataclan venue, where a terror attack at an Eagles of Death Metal show resulted in the death of 118 people, an unknown musician set up a grand piano outside the concert hall and delivered a poignant, instrumental take on John Lennon's "Imagine." A peace sign adorned the musician's piano.

Flowers, candles and memorials were also set up outside the Bataclan, the epicenter of the deadliest day in France since World War II. Lennon's 1971 classic features the lyrics "Imagine there's no countries / It isn't hard to do / Nothing to kill or die for / And no religion too." Those lyrics especially resonate in the aftermath of the Paris terror attacks, a massacre perpetrated by the Islamic State (ISIS)

France has declared three days of national mourning following Friday's attacks that killed 127 people.