In the early 19th Century Paganni was considered the greatest musical virtuso performer of his time. He thus inspired Franz List who legend has it holed himself and practiced for hours on end to raise the level of virtuosity on the piano to new heights comparable to or above the level of Paganni on the violin. In addition to being acknowledged as probably the greatest pianist of his time he was also quite the showman who had women swooning and throwing their undergarments on stage. The TRUE precursor to the 20th Century performers we know. In addition he is certainly among the greatest composers of the Romantic era. Not too shabby. The greatest are ultimately the most original in their field, the ones who inspire others to new heights. There is no answer. Who would argue with the following - Prokoviev, Rachmaninov, Gershwin, Sinatra, Vaughn, Fitzgerald, Parker, Ellington, Davis, Frank Zappa, Jimi Hendrix, John McLaughlin, Al DiMeola, Jeff Beck, Jimmy Page, Robert Plant, John Lennon, McCartney, Brian Wilson, Muddy Waters and many more. There is so much to musicianship than can't be measured by the question "Who is best"? Who is technically the best? Who is artistically the best? Who is the most expressive? Who is the most original? Who is the most inspiring?
Best musician in the world?
A question posed in another thread, in my view, although musicianship is hardly a sport to be measured as such, the most universally prodigious musician is probably Shawn Lane. He is definitely the world's most phenomenal/inimitable electric guitarist. And he is a world-class pianist and saxaphonist as well.