Prior to coming together to help form Prophets of Rage, guitarist Tom Morello, bassist Tim Commerford and drummer Brad Wilk rose to prominence as three-fourths of Rage Against the Machine — and then went on to co-found Audioslave with Soundgarden singer Chris Cornell.

Although that supergroup wasn't destined to last, their bond with Cornell remained, and they've paid tribute to their former bandmate more than once since his death last year — an honor they offered again during a March 20 stop in Auckland, New Zealand, during which they were joined by System of a Down singer Serj Tankian for a performance of the Audioslave song "Like a Stone."

Tankian has joined Cornell's former collaborators to pay tribute on more than one occasion since the singer's death. When Cornell was posthumously awarded the Human Rights Watch's Promise Award late last year, Tankian was on hand to offer a few words of praise, singling out Cornell's recording of the soundtrack anthem for the Armenian genocide drama The Promise while pointing to a life and career of exemplary compassion.

"We're here tonight to honor a compassionate, just and gentle human being who I had the great pleasure to call my friend, Chris Cornell," Tankian said. "His voice was always honest, caring and real. It's difficult to successfully lie through art. The man himself was always honest, caring and real."

Cornell's widow Vicky was also on hand for the Human Rights Watch ceremony, and she shared her gratitude for Tankian's appearance with Prophets of Rage in Auckland, tweeting a link to some fan-filmed footage of the performance — which you can watch above — and thanking the musicians for "honoring and keeping [Cornell's] memory alive."

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