=Summary=.—The work of this period can hardly be over-estimated. First we see the influence of the Gothic in architecture, producing a corresponding unity in music; a unity which was concomitant with Measured or Mensural Music. We next see the attempt to combine metrical with unmetrical forms in the Organum Purum, and the final result in the strict form of Organum. Then we note the freedom shown in the Conductus, Roundel and Motet, as well as freedom in the use of more pleasing intervals, with the tendency to eradicate consecutive fourths and fifths; the use of contrary motion instead of parallel, and the consequent melodic freedom of the voices, and finally the use of Imitation, though perhaps unintentionally, except in the Roundel. This period then marks the acquisition not only of new intervals, new forms, new styles of melodic writing, imitation, measured music and simple counterpoint of note against note, but also forms the foundation for a rapid development by bequeathing to the Gallo-Belgic School a wealth of material, bound up with rules and only half-suspected as to its value, it is true, but broad and firm enough to sustain a mighty structure of true Polyphonic Music. REFERENCES. Naumann.—History of Music, Vol. I. Grove.—Dictionary of Music and Musicians. Article on Schools of Composition, section relating to early French music. Hope.—Mediæval Music. Technical Explanation of Mensural Music. Oxford History of Music, Vol. I, pages 74-388. Technical explanation of measured music. Luebke.—History of Art, for an account of Byzantine, Romanesque and Gothic Architecture. Guizot.—History of France, for an account of Paris in 1100, with a statement of manners and customs. QUESTIONS AND SUGGESTIONS. How did art influence music? What made Paris the centre of Europe? What was Measured Music? What forms of music were developed in this period? Explain them. Why is Imitation a logical process toward securing Unity in musical construction? Who are leading composers of this period? What are the successive steps of development as shown in this period? The historical period corresponding with this lesson extends from the death of William Rufus, son of William the Conqueror, to the death of Richard the Lion-Hearted, and includes the Crusade in which that hero was the principal figure. It will be remembered that Richard was a great patron of minstrelsy. LESSON X. THE GALLO-BELGIC SCHOOL.