Lorenz Christoph Mizler in 1742. Fux dedicated it to Emperor Charles VI. The work is divided into two major parts. In the first part, Fux presents a summary of the theory on Musica Speculativa, or the analysis of intervals as proportions between numbers. This section is in a simple lecture style, and looks at music from a purely mathematical angle, in a theoretical tradition that goes back, through the works of Renaissance theoreticians, to the Ancient Greeks. Fux explains that intervals in exact mathematical proportions result in larger and smaller half tones, and he also mentions that some organists added extra keys (split halves to use smaller and bigger half tones), but that adding extra keys on a keyboard was problematic and for this reason they divided every note in "" (two equal parts), resulting in equal temperament. He continues: The works of Mersenne, Cicero and Aristotle are among the several references quoted by Fux in this section. The second part, on Musica Pratica, is the section of this treatise where the author presents his instruction on counterpoint, fugue, double counterpoint, a brief essay on musical taste, and his ideas on composing sacred music, writing in the a cappella and in the recitativo style. This part is in the form of a dialog, between a master (Aloysius, Latin for Luigi, who is meant to represent Palestrina's ideas) and a student, Josephus, who represents Fux himself, a self-admitted admirer of Palestrina. At the outset, Fux states his purpose: "to invent a simple method by which a novice can progress, step by step, to attain mastery in this art." and gives his opinion of contemporary practice: "I shall not be deterred by the most ardent haters of school, nor by the corruptness of the times." He also states that theory without practice is useless, thus stressing practice over theory in his book. While Gradus ad Parnassum is famous as the origin of the term "species counterpoint", Fux was not the first one to invent the idea. In 1610, Girolamo Diruta, a composer of the Venetian school, published Il Transilvano, which presented the Renaissance polyphonic style as a series of types: one note against one note, two notes against one note, suspensions, and so forth. Fux's work repeated some of Diruta's, possibly coincidentally, since he is not known to have had a copy. In species counterpoint, as given in Fux, the student is