The memorandum book has a few entries which relate to Haydn. On page 7, that which contains the 15 ducats on the 12th of October, 1792, there is a column of numerals, the first of which reads, “Haidn 8 groschen”; the other twelve, except a single “1,” all “2”; and on the two pages which happen to have the dates of October 24 and 29, 1793, are these two entries: “22 x, chocolate for Haidn and me”; “Coffee, 6 x for Haidn and me.” These notes simply confirm what was known from other sources, namely, that Beethoven began to study with Haydn very soon after reaching Vienna and continued to be his pupil until the end of the year 1793.[64] They indicate, also, that the scholar, whatever feelings he may have indulged towards the master in secret, kept on good terms with him, and that their private intercourse was not confined to the hours devoted to lessons in Haydn’s room in the Hamberger house, No. 992 on the (no longer existing) Wasserkunstbastei. Concerning the course of study during that year, nothing can be added to the words of Nottebohm (“Allg. Mus. Zeitung,” 1863-1864), founded upon a most thorough examination of all the known manuscripts and authorities which bear upon this question. Of the manuscripts Nottebohm says: “They are exercises in simple counterpoint on six plain chants in the old modes.... He must have written more.” But what? On this point there are no indications to be found. It may be accepted with considerable certainty that the contrapuntal exercises were preceded by an introductory, though probably brief, study of the nature of consonances and dissonances. For this the last chapter of the first book of Fux’s “Gradus ad Parnassum” might have served. But this (adds Nottebohm) would not have sufficed to fill the entire period. In view of Haydn’s predilection for Fux’s system it is not conceivable that there were preliminary exercises, say in the free style or in the modern keys; there remains, therefore, no alternative but to go back further and opine that the study with Haydn began with the theory of harmony and exercises in which the system of Philipp Emanuel Bach might have been used.