My dear Derek,
Duende is new to you? A crying shame. I learnt about duende round about the time I was doing Art History alongside Anthony Gormley in 1970. Anthony's line drawings of female figures in those days had duende but I did not learn the word in the History of Art Department or visiting Anthony. I learnt it from a guy from the Slade who was one of a group of practical art students who had brought an exhibition up to show along the Cam for the May Ball season. His stuff had duende. I came to understand more about it from Raphael Nadal, a remarkable man who lived duende, even in the briefest of conversations. He had been a friend of Lorca and Bunuel and come to the UK as refugee, journalist, academic and source of delight to everyone, including New Year's Eve parties where one could meet people like Segovia, Cecil Collins or indeed Ernst Gombrich. 

Duende is more than just pazazz or 'it works'. It is the sense of a spirit (or soul) that has reached beyond yours and lets you get a glimpse of where to - in whatever context. Sharks in tanks do not for me have duende! It is not just the Hagia Sophia, or even the fact that someone built the Hagia Sophia, but also the fact that some guy thought the Hagia Sophia and knew what it would speak. It is specifically used to describe dancing and the film 'Blood Wedding' by Saura (based on the Lorca play) is probably the best captured example I know. But it is also used as a more general concept. It is probably instructive that the English speaking world has no equivalent. Maybe duende does not cover Constable and Gainsborough too precisely! I would bet the Brazilians have a Portuguese version. To be honest I am not quite sure how you can do aesthetics without it.

Jo E