Germany's famous Wacken Open Air festival will be wrapping it up tonight (Aug. 6) with a number of iconic rock and metal acts having already taken the stage. Last night (Aug. 5), Arch Enemy frontwoman Alissa White Gluz joined former Nightwish singer Tarja Turunen onstage for a dynamic metal duet.

White-Gluz provided guest vocals on Turunen's new solo effort, The Shadow Self, singing on the song "Demons in You." Addressing the crowd, Turunen explained she had been "waiting for this moment," introducing her friend from Arch Enemy, which was met with wild applause from the sea of metalheads. The two began clapping in unison to get the crowd moving as the funky bass line took over.

As a plume of smoke shot up from the stage, the stomping rhythm kicked in and the duet was underway. White-Gluz employed her guttural vocal style as Turunen's operatic voice provides a lighter complement to the darker shade of the demonic bellowing. Coming together with wondrous, clean sung harmonies in the chorus, the performance was truly electrifying.

The pairing was also of particular interest for Nightwish fans as White-Gluz had once filled in for then singer Anette Olzon for one night in 2012.

Tarja's timing was impeccable as the night also marked the release date of her fifth studio album, The Shadow Self. The record was the successor to the singer's previous 2016 EP, The Brightest Void, which featured six new tracks and three covers including gust spots from Red Hot Chili Peppers drummer Chad Smith and Hanoi Rocks singer Michael Monroe.

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