I think the longest medley we ever did was about 45 minutes i.e. the whole set. That was in a Conservative Club (hey - it's all money!) and the poor old dears were exhausted by the time the bingo came on! We did all songs from our 'sick' list (yes, it is called that ) - Amarillo, Ten Guitars, Obla-dee, Country Roads, etc ad nauseum. We were in stitches, tears of laughter...