Serialism allowed Copland a synthesis of serial and non-serial practices. Before he did this, according to musicologist Joseph Straus, the philosophical and compositional difference between non-tonal composers such as Schoenberg and tonal composers like Stravinsky had been considered too wide a gulf to bridge. Copland wrote that, to him, serialism pointed in two opposite directions, one "toward the extreme of total organization with electronic applications" and the other "a gradual absorption into what had become a very "freely interpreted tonalism" Copland". The path he said he chose was the latter one, which he said, when he described his "Piano Fantasy", allowed him to incorporate "elements able to be associated with the twelve-tone method and also with music tonally conceived". This practice differed markedly from Schoenberg, who used his tone rows as complete statements around which to structure his compositions. Copland used his rows not much different than how he fashioned the material in his tonal pieces. He saw his rows as sources for melodies and harmonies, not as complete and independent entities, except at points in the musical structure that dictated the complete statement of a row.