In 1983, some of the greatest rock musicians of all time came together for a special cause. There was a concert in England for Action into Research for Multiple Sclerosis (ARMS).
The concerts featured individual sets from each musician followed by a group jam. A few videos of the shows exist on YouTube.
First, watch Jimmy Page play an instrumental version of Stairway to Heaven. He is eventually joined by Clapton and Beck. Then, watch all three guitarists jam on Layla.