This is what we found on Wikipedia regarding the Motley Crude:

The Moscow Music Peace Festival was a rock concert that took place in the USSR on 12 and 13 August 1989 at Central Lenin Stadium (now called Luzhniki Stadium) in Moscow. Occurring during the glasnost era, it was one of first hard rock and heavy metal acts from abroad that were granted permission to perform in the capital city, (being the first the ten shows the British band Uriah Heep played from 7 to 16 December 1987 at the Olympic Stadium). Over 100,000 people attended and it was broadcast live to 59 nations including MTV in the United States. The event promoted understanding between the Western Bloc and the Eastern Bloc during the Cold War and also raised money to help those addicted to drugs and alcohol. The concert featured six bands from abroad and three Russian bands. The concert ended with the various band members participating in jam session. An album and documentary were released.

It inspired the 1990 song "Wind of Change" by Scorpions, one of the bands that performed at the concert. The song became one of the best selling singles of all time.

Modeled as a "Russian Woodstock" the concert was a joint production by Russian musician Stas Namin and American music manager Doc McGhee.