The imitation of the classics had also a decided effect on the technique of French verse and on the linguistic principles of the Pleiade. Enjambement (the carrying over into another line of words required to complete the sense) and hiatus (the clash of vowels in a line) were both employed in Latin and Greek verse, and were therefore permitted in French poetry by the new school. Ronsard, however, anticipated the reforms of Malherbe and the practice of French classic verse, in forbidding both hiatus and enjambement, though in a later work of his this opinion is reversed. He was also probably the first to insist on the regular alternation of masculine and feminine rhymes in verse. This had never been strictly adhered to in practice, or required by stringent rule, before Ronsard, but has become the invariable usage of French poetry ever since. Ronsard regards this device as a means of making verse keep tune more harmoniously with the music of instruments. It was one of the favorite theories of the Pleiade that poetry is intended, not to be read, but to be recited or sung, and that the words and the notes should be coupled lovingly together. Poetry without an accompaniment of vocal or instrumental music exhibits but a small part of its harmony or perfection; and while composing verses, the poet should always pronounce them aloud, or rather sing them, in order to test their melody.[395] This conception of music "married to immortal verse" doubtless came from Italy, and is connected with the rise of operatic music. De Laudun (1598) differs from the members of the Pleiade in forbidding the use of words newly coined or taken from the dialects of France, and in objecting to the use of enjambement and hiatus. It is evident, therefore, that while the influence of the Pleiade is visible throughout De Laudun's treatise, his disagreement with Ronsard and Du Bellay on a considerable number of essential points shows that by the end of the century the supremacy of the Pleiade had begun to wane. The new school also attempted to introduce classical metres into French poetry. The similar attempt at using the ancient versification in Italy has already been incidentally referred to.[396] According to Vasari, Leon Battista Alberti, in his epistle, "Questa per estrema miserabile pistola mando,"