The opera ends with a dance. In his "Tancredi e Clorinda," an intermezzo produced in Venice in 1624, Monteverde introduced special instrumental effects which were to become of so great importance in opera. These effects I have already described in Chapter XI, and it is necessary to add here only the statement that they were used, not simply as descriptive of action, but also to aid in conveying to the minds of the auditors the impetuosity and passion of the combatants in the remarkable scene of the fight. It gives one something of a shock to find Monteverde indicating the galloping of horses and the fierceness of their riders, rudely indeed, but with the same musical methods as Wagner employed, with their modern development, in his "Ride of the Valkyrs." Monteverde was, indeed, the Wagner of his time. He broke so completely away from old conventions that Artusi, a writer of Bologna, accused him of having lost sight of the true office of music, "to please the ear." One of the remarkable things (remarkable at that time) done by Monteverde was to introduce the chord of the dominant seventh unprepared. I shall not undertake to explain the nature of this novelty in harmony, lest I merely confuse the lay reader, but shall ask him to content himself with the statement that such an introduction produced one of those sharp dissonances so common in the music of to-day, and used to express passion. Monteverde began to use these dissonances in his madrigals, of which the Fifth Book, published in 1599, aroused Artusi's ire. But the tremendous effect of the dissonant progressions in "Arianna" quite demolished all the arguments of the opponents of the novelty. Their employment was one of the practices which led directly away from the tonality of the old ecclesiastical scales and toward the modern major and minor keys. Dr. Parry's comments on the work of Monteverde are so pertinent and so lucid that I cannot do better than to quote a part of them:--