But the composers of the first Netherland period employed kinds of canonic writing which are now looked upon as mere curiosities. Among these were the repetition of the cantus firmus beginning with the second note and ending with the first; the repetition with the omission of all the rests; the perfect repetition of the whole melody; a repetition half forward and half backward; and another with the omission of all the shortest notes. Naumann is of the opinion that these forms "arose from an earnest desire to consolidate a system of part-writing which could only exist after a complete mastery had been obtained over all kinds of musical contrivances." Kiesewetter, also generous in his views, says that these writers excel their predecessors in possessing "a greater facility in counterpoint and fertility in invention; their compositions, moreover, being no longer mere premeditated submissions to the contrapuntal operation, but for the most part being indicative of thought and sketched out with manifest design, being also full of ingenious contrivances of an obligato counterpoint, at that time just discovered, such as augmentation, diminution, inversion, imitation; together with canons and fugues of the most manifold description." Of Ockeghem in particular, Rochlitz ("Sammlung vorzüglicher Gesangstücke," Vol. I., p. 22) says: "His style was distinguished from that of his predecessors, especially Dufay, principally in two ways: it was more artistic and was not founded on well-known melodies, but in part on freely made melodic movements contrapuntally developed, which rendered the style richer and more varied."