It is interesting to recall the origin of our words "treble" and "discant." The latter was derived from the first attempts to break away from the monotony of several persons singing the same melody in unison, octaves, fifths, or fourths. In such cases the original melody was called _cantus firmus_ (a term still generally used in counterpoint to designate the given melody of an exercise to which the student is to write other parts), the new melody that was sung with it was called the _discant_, and when a third part was added, it received the name _triplum_ or _treble_. As Ambros remarks, this forcible welding together of different melodies, often well-known old tunes, secular or derived from the church chants, was on a direct line with the contemporary condition of the other arts. For instance, on the portal to the left of the Cathedral of Saint Mark, at Venice, is a relief, representing some Biblical scene, which is entirely made up of fragments of some older sculptured figures, placed together without regard to anatomy in much the same brutal fashion that the melodies of the time were sung together. The traces of this clumsy music-making extended down to Palestrina's time, and became the germ of counterpoint, canon, and fugue, constituting (apart from the folk song) the only music known at that time. This music, however, very soon developed into two styles, one adopted by the church, the other, a secular style, furnishing the musical texture both of opera and other secular music. The opera, or rather the art form we know under that name (for the name itself conveys nothing, for which reason Wagner coined the term "music drama") broke away from the church in the guise of Mysteries, as they were called in mediaeval times. A Mystery (of which our modern oratorio is the direct descendant) was a kind of drama illustrating some sacred subject, and the earliest specimens laid the foundation for the Greek tragedy and comedy. We still see a relic of this primitive art form in the Oberammergau Passion Play. We read of the efforts made, as early as the fifth century, to hold the people to the church; among other devices employed was that of illustrating the subjects of the services by the priests performing the offices being dressed in an appropriate costume. Little by little the popular songs of the people crept into the church service among the regular ecclesiastical chants, thus foreshadowing the beginnings of modern opera; for after a while, special Latin texts were substituted for the regular service, the mimetic part of which degenerated into the most extraordinary license as, for instance, in the "Feast of Asses" (January 14) which may be called a burlesque of the mass, and which has been described in a former chapter.