It was called "Rock Aid Armenia" and it was a benefit organized at first by John Paul Jones (former Zep bass player). All this was around 1990.
The concept was that he would gather players from all the legendary rock bands to do one classic track at a time. However Jones soon left and I believe they never got past "Smoke on the Water".
The weird thing here is that Gillan had just left Purple and yet you can see him and Blackmore together again!!!
Another piece of trivia-from-way-back-when: It was supposedly at this event that Gillan adviced Dickinson to follow his muse and do a solo album (which became "Tattoed Millonaire").
Those were the days...
![Smile](https://www.progarchives.com/forum/smileys/smiley1.gif)
PS: There's also Brian May, Tony Iommi, Paul Rodgers, Keith Emerson, Brian Adams, etc. in there.