To me, a great singer - it's not a sport - so it's not about just being good technically. It has to move you, it has to leave you going "I've got goosebumps". I've not really bothered to listen to
Eva Cassidy from a technical point of view, because I've never had to. I've just enjoyed her music and thought "Gosh, she just touches the soul". But because of the documentary I then studied her voice and technically she is like a master of her craft.