Went to a Kristofferson concert many, many years ago at Constitution Hall in DC. Rita Coolidge was singing backup and harmonies. At the beginning of the 1st set someone in the audience ran up and sat a fifth of Jack on the edge of the stage. Kris started taking a slug after every song and half way through the set he was weaving. From then on he didn't finish any song he started - just stopped and complained to the sound crew that the sound was terrible. Didn't come out for the second set and Rita Coolidge filled in.