Longest ballad in recent tradition??

Possibly Gordon Hall's The Ballad of Bob Copper in which Gordon Hall wrote a hilarious account of Bob's life culled from stories that he heard in a secret meeting with John & Jill a few weeks before Bob Copper's 80th birthday party which we held for him at our folk club in Lewes. I didn't time it on the night though John Howson recorded the whole evening and sent me the 3 1/2 hours of cassettes of the entire evening. I still have them in one of these many boxes of cassettes that I am going to organise and catalogue one of these days. I believe that it lasted 26 minutes and the look on Bob's face as stories that he thought were only known to the family unfolded only added to the hilarity of the occasion.

The only problem would be with the word 'tradition' because I don't know if a song that I suppose was only ever sung once can be considered to come into that category.