Claudio Arrau LeÃ n ( February 6 , 1903 - June 9 , 1991 ) was a Chilean classical pianist and one of the greatest classical pianists of the 20th century . Claudio Arrau LeÃ n ( February 6 , 1903-June 9 , 1991 ) was a Chilean-American pianist known for his interpretations of a vast repertoire spanning from the baroque to 20th-century composers , especially Beethoven , Schubert , Chopin , Schumann , Liszt , Brahms and Debussy . He is widely considered one of the greatest pianists of the twentieth century .