Just watched a video on meantone with a demonstration. Effectively in equal temperament G sharp and A flat are not exactly the same note and the idea that flats and sharps are the same note is a modern thought. So there I always thought the circle was unbroken! I'm not sure I would like to attempt to play an enharmonic key board even if I could. I have enough trouble keeping my guitar in tune as it is. I am very interested in your comment about singers drifting into Meantone. Could you name an example when and if you have time. By the way thank you so much for the help.