System Of A Down are joined by Deftones frontman at Rock in Rio – watch

The Cali rockers got screaming help on 'Toxicity' courtesy of Chino Moreno

System Of A Down were joined by Deftones frontman Chino Moreno during their headline set at Rock in Rio this week.

Moreno accompanied SOAD’s frontman Serj Tankian on vocals at the Brazilian festival when they played ‘Toxicity’, from their 2001, US Number One album of the same name.

The group are currently on a ‘Wake Up the Souls’ tour to mark 100 years since the Armenian Genocide during World War I. The tour ends on October 6 in Mexico City, and included a free show in Armenia – also the band’s first ever gig there – on the day before the annual genocide remembrance day.

Drummer John Dolmayan told Billboard that, as an Armenian, the show was “more impactful” for him and that “it’s something that transcends music. This is more important than the next System Of A Down album.”

There is a sixth SOAD record on its way. Bassist Shavo Odadjian confirmed earlier this year that the band are working on a new album. He said: “We’ve written some songs. We’re keeping it to ourselves. We’re getting back to the bullshit of being together.”

Watch System Of A Down and Deftones perform ‘Toxicity’ in Brazil here: