ABC
Leto introduced Dion's performance with an emotional speech recalling a performance he did with his band Thirty Seconds to Mars at the Bataclan (one of the targets of the Paris attacks) earlier this year.
"We decided to play a little impromptu show at a classic venue called the Bataclan. It was beautiful, peaceful, and unforgettable. What a difference a day makes," he said. "Seven months later, on the evening of November 13, 2015, that same venue, Bataclan, was under siege. One in the series of a terrorist attack on Paris that changed the world forever. 129 innocent people died, 368 were injured, and another 7 billion will forever be scarred by this horrific and senseless tragedy."
Leto mentioned friends and colleagues he knew at the venue that night and honored his friend Thomas Ayad, who was killed.
He also brought up Antoine Leiris, a Frenchman whose wife was killed, who wrote a touching tribute to his wife and had a message for ISIS. Leiris wrote:
"Friday night, you took an exceptional life. The love of my life, the mother of my son. But you will not have my hatred... You want me to be scared, to view my countrymen with mistrust, to sacrifice my liberty for my security - you lost. We are just two now, my son and me. But we are stronger than all the armies in the world."
Leto concluded his speech with a message of solidarity.
"Tonight we honor the victims of the unimaginable violence that has taken place this year in Paris and around the world," he said. "France matters, Russia matters, Syria matters, Mali matters, the Middle East matters, the United States matters - the entire world matters and peace is possible."
Dion performed a cover of French icon Edith Piaf's "L'hymne À l'amour" in front of a screen projecting photos of Paris.
Watch her performance below: