The development of secular music at this time is even more interesting and instructive than that of religious music, but it would require a chapter for its proper treatment; and as it was not long in abandoning the basis of counterpoint and entering: upon the free arioso style of the opera (in 1600), it may be dismissed briefly. The reader must understand that popular music in the form of folk-songs has existed from time immemorial. The Netherlands masters frequently employed the melodies of these songs (and the words, too) in their masses, which gave rise to abuses removed by the Council of Trent in 1565. In the third period of the Netherlands school, however, the masters of scientific music began to compose music for the general public, and the result was the madrigal form, which has survived till to-day. This was a natural result of Josquin's aiming at beauty in music. The next step after euphony was naturally toward expression, and the first attempts at expression were, of course, imitative. In other words the secular composers turned to nature and tried to imitate her sounds in music. These men were the first who practised what we may call tone-photography in contradistinction to tone-coloring, which goes deeper. When Beethoven introduced the cuckoo in the pastoral symphony he practised tone-photography. The works of Gombert and Jannequin abound in skilful writing of this kind. Gombert's "Bird Cantata" is a clever and humorous composition. Jannequin's "Cris de Paris" is a musical imitation of the street cries of a great city, and his "Le Battaille" is a picture of a battle. When we remember that these works were written for voices in four parts, we are astounded at the technical accomplishments of these old masters. This ambition to tell some kind of a story in music affected even the religious compositions of the day, and one of Willaert's motets tells the history of Susannah. This work was plainly the precursor of the oratorio form, which first took recognizable shape in Cavaliere's "L'Anima è Corpo," produced in 1600. [Illustration: JAN PIETERS SWELINCK.] The fourth and last period of the Netherlands school was distinguished by two features: the production of a master whose genius eclipsed the brilliancy of all his predecessors and whose music was a logical outcome of their labors, and secondly, the completion of the mediæval development of counterpoint. The mission of the Netherland masters was ended, and new art-forms came to supersede the ecclesiastical canon. This now descended from its leadership of the musical army and took that place in the ranks which it maintained till the supremacy of Haydn and the sonata form.