The postcard was printed before the concert in two different variants.
The 1st printing A postcard presents an all-over purple background with blackened upper left and right corners. It generally measures 5" x 7", but there are also wider versions of this variant, which measure around 5 3/8" x 7".
The 1st printing B postcard is identified by a 1/4" light blue strip on the right hand side of the postcard. It has a blackened upper left corner but not the right. It measures 5" x 7".