Who is a Polish politician that was also famous for performing Piano Concerto No. 4 by Anton Rubinstein?
Ignacy Jan Paderewski Ignacy Jan Paderewski, GBE (] ; 18 November [O.S. 6 November] 1860  – 29 June 1941) was a Polish pianist and composer, politician and spokesman for Polish independence. He was a favorite of concert audiences around the world. His musical fame opened access to diplomacy and the media.
Juliusz Wertheim Juliusz Edward Wertheim (24 September 1880 – 6 May 1928), sometimes known as Julius or Jules Wertheim, was a Polish pianist, conductor and composer, a member of a prominent family, who had a significant influence on the career of Arthur Rubinstein.