“…We are aw11re that some of our readers may not be familiar with the works and theories of Schenker. Since many of Schenker's works are still not available in translation, we gladly refer interested readers to some of Schenker's theories available in the works of other theorists, 1 including notably: Katz (1935), Sessions (1935), Mann (1949), Jonas (1954), Forte (1959), Salzer (1962), Beach (1969), Komar (1971), and Rothgeb ( 1972), among others. In spite of the controversy which surrounds Schenker's theories, even those who are not at all in sympathy with his ideas tend to accept, even if reservedly, the principle of the existence of the three structural levels in all tonal music.…”