This was a special presentation to celebrate the 250th birthday of Detroit, performed before an audience of approximately 5,000, at the Masonic Auditorium. It was broadcast as part of the Theatre Guild on the Air series. This program was the 250th in the series.
At 49 minutes (several minutes of which were opening and closing announcements), this was a much-abbreviated version of the script. It was adapted by Robert Anderson (later known as the author of plays including Tea and Sympathy, You Know I Can't Hear You When the Water's Running and I Never Sang for My Father).
The performance and the broadcast were on November 25, 1951. A Worldcat page says that the performance and the first broadcast were on July 24, 1951, with a rebroacast on November 25, but that is contradicted by an article in the Detroit Free Press from Thursday, November 22, 1951. The article states that Jane Powell, John Lund and Kenny Delmar are in town and will be there through Sunday for the performance of Allegro at the Masonic Auditorium.