Ives published more than 100 of his songs. He was a very good pianist and the piano parts are often quite difficult. They include bitonality and pantonality.. Although he is now best known for his orchestral music, he composed two string quartets and other chamber music. His organ piece "Variations on "America"" (1891), takes the tune "My Country, 'Tis of Thee" (which is the same tune as "God Save the Queen ") and changes it in several amusing variations, using a march, a ragtime and bitonality. it was not published until 1949. The variations differ sharply: a running line, a set of close harmonies, a march, a polonaise, and a ragtime allegro; the interludes are one of the first uses of bitonality.