CSN&Y live at Wembley Stadium on September 14, 1975.

Joni Mitchell joins the group to provide harmony on “Helpless.”

The day long concert included appearances Mitchell, The Tom Scott Band, The Band and Jesse Colin Young.

The Wembley set was the last concert of the CSN&Y 1974 reunion tour and was marked by a lot of tension between the members of the group fueled by cocaine, Stills’ tenuous grip on reality and quarreling girlfriends. Young wasn’t into the drama and kept at a distance, traveling alone with his son in a camper van. But despite the animosity within the band, the show has moments of greatness.