 Complete the following phrase:  To promote its latest album, Pantera began the Cowboys from Hell tour alongside thrash acts Exodus and Suicidal Tendencies. In 1991, Rob Halford performed with the band onstage, which led Pantera along with Annihilator to open for Judas Priest on its first show in Europe. They also opened for other bands like Sepultura, Fates Warning, Prong, Mind Over Four, and Morbid Angel, and co-headlined a North American tour with Wrathchild America. The band eventually landed a billing for Monsters in Moscow with a hrefACDCACDCa and Metallica in September 1991, where they played to a crowd of over 500,000 in attendance to celebrate the new freedom of performing Western music in the Soviet Union shortly before its 