The secular impulse from whence sprang the simple melodies of the minnesingers and troubadours soon found a channel for fuller expression in the art-music of the period immediately following the decay of chivalrous song. It was inevitable that the tendency toward secularization, already strongly developing in the other arts--notably painting and architecture--should extend to music also. The beneficent alliance of music and poetry both in the service of the church and in the less pretentious effusions of the secular poet-musicians of courtly estate naturally led thought to a desire that music should be the helpful companion of poetry in all her wanderings, in the domain of secular experiences as well as religious. As soon as the spirit of polyphony had been firmly established in ecclesiastical music, the church composers began to turn their attention to the rapidly widening field of secular poetry for material on which to exploit their newly-found contrapuntal skill. The first application of the principles of polyphony to secular art-music manifested itself in the French _chanson_ and the Italian _frottola_. Both of these were merely popular melodies brought within the domain of the contrapuntal principle. The _frottola_ seems to have been always set for four voices in very simple movement, the _chanson_ for either three or four voices. These two forms soon merged into the madrigal, which expanded its scope so as to include almost any lyric composition of delicate texture dealing with thoughts of rustic humor, sentiment, or passion, couched in the language of everyday life. The madrigal in time developed into a special department of composition, having a brilliant history of its own and engaging the interested attention of nearly every noted composer from the fourteenth to the sixteenth century. The word, whose derivation is hopelessly entangled in a maze of disputed sources, appears as early at least as the fourteenth century in connection with pastoral or rustic poems of amorous character, and very naturally the name was soon transferred to the music to which the words were set.