From the pianist Piotr Anderszewski's first comments in 'Unquiet Traveller' ('Voyageur Intranquille'), a new documentary film that follows him on a concert tour by train through his native Poland, you would think that this fiercely individual artist found being a pianist an agonizing impossibility. In a winter coat and a hat with thick wool lining, Mr. Anderszewski walks solita...
