The genres of his compositions included operas, oratorios, masses, requiems, motets, sonatas, and keyboard pieces. His formulation of rules for counterpoint is found in the book "Gradus ad Parnassum" which was employed by both Mozart and Haydn and typifies "the" zenith of contrapuntal writing. For eight years Fux was the choirmaster at St. Stephen's followed by a vice-Kappelmeister position at the court of Charles VI shortly followed by a Kappelmeistership. He served for the Hapsburg court under three different kings. According to Fux the greatest influence he felt was from the work of Palestrina. Perhaps his most representative work was the opera "Costanza e Fortezza" in which Fux successfully developed a synthesis between counterpoint and facility keeping the work light despite the usual burden of note-for-note polyphony. Fux intentionally wrote without a specific tendency toward nationalism nevertheless retaining tradition. His "Te Deum" employed the use of double choirs, a contrasting solo voice with full choir, a blend of arias, recitatives, deep but abiding pathos, expressive arias and ensemble work as well. ~ Keith Johnson