The 2 day "Summer Rock Festival" took place at the Radstadion in Frankfurt, Germany on July 21 and 22 1973.
The lineup for the two shows included:
Saturday, July 21, 1973
Black Sabbath (cancelled)
Curved Air
Gentle Giant
Sly & the Family Stone
Tempest
Sunday, July 22, 1973
Chuck Berry (unscheduled)
Faces (introduced by Keith Moon)
Nazareth
Rory Gallagher
Others in the intended lineup included: Paul McCartney And Wings (cancelled), Black Sabbath (cancelled), Canned Heat (cancelled), The Spencer Davis Group, Hardin & York, Marsha Hunt, Back Door, Heavy Metal Kids & Blue.