We are limited by who have on disc or have heard in person. This may seem like an obvious statement, but many greats are not properly represented in the current discography - and they will never be. They performed in an era where recording technology was in its infancy both in terms of quality and quality (the lengths of their recorded performances) and reproduction. And even remastering does not help a lot. A good, but not great voice recorded today may sound a lot better than a great voice recorded 50 years ago. A shame, really, but also reality.
