It is impossible to get an impartial answer to thi questio. For a start, we don't have access to the plaaying skills of all the musicians before sound recording was discovered. Secondly, there are too many people when, refering to the skill of artists, often confuse, like with good, they vote for their likes rather than an objective vote for best. Then we have to consider one instrument against another, is who you consider the best, say, violinist, better then your percieved, best trumpet, or guitar player. To try and be objective, I will stick my neck out and say that I think the best musician in the era of sound recording, is the guitarist, Andres Segovia.