Former ACCEPT and current U.D.O. frontman Udo Dirkschneider will join Finnish monster hard rockers LORDI for at least one song during their appearance at this year's Wacken Open Air festival, which is scheduled to take place July 31 - August 2, 2008 in Wacken, Germany.
Dirkschneider makes an appearance on the song "They Only Come Out At Night" (listen to the audio below) on LORDI's latest album, "The Arockalypse", which came out in March 2006.