The several simultanous programmes collectively known as the Edinburgh Festival take over the Scottish capital each August, bringing thousands of shows in around-the-clock performances.
I have been collecting materials for this book for more than twenty years; not indeed by way of constant work, but off and on as detailed below.
The sources from which these materials were directly derived are mainly the following.
Most of these shows went on tour after Edinburgh, many eventually playing London.
Horton Foote may be America's best semi-unknown playwright.
From the brief description I just gave, you could write the whole play, and might well come up with more interesting interactions than he does.