Both variants of the pre-concert printed postcard measure 4 1/2" x 6 7/8".
The 1st printing A has a Place Stamp Here box on the reverse side.
The 1st printing B has a Bulk Rate mark on the reverse side.
There were also some pre-concert double-sized mailers printed that were conjoined with the BG109 image. They measure 4 1/2" x 13 7/8".