A peculiarity of the single voice is the fact that while capable of singing melodies of an almost infinite variety it seems to the cultured ear to need support of some kind. While untutored people are content to listen to the singing of a voice without any accompaniment, a certain degree of culture brings with it a sense of bareness conveyed by a performance of this kind. Toward the close of the dark ages this feature of the voice attracted the attention of the church musicians. They hit upon the device of having a second voice accompany the first, singing another melody which should have a pleasing effect in conjunction with the original one. This marked the beginning of counterpoint, and it gave a direction to the art of music from which it did not depart for many centuries. With the gradual extension of polyphonic writing the education of singers became constantly a more complex and exacting matter. Greater demands were made on both the voice and the musicianship of the choral singer. No great modification was, however, made in the system of instruction; this developed along the lines already marked out for it. Sight singing continued to be the basis of musical education. As time went on it became necessary for the singers to master the system of musical notation, and this was accomplished by a farther extension of the course in sight singing. An understanding of the rules of counterpoint was not obligatory on the part of the choristers, but many of them received sufficient instruction to fit them for both composition and teaching. Composers and teachers were without exception graduates of the choir schools; a musical education could not be obtained elsewhere. Music study had indeed no other purpose than to train students in the music of the church. Instruction in counterpoint and composition was not undertaken until the students had mastered the rudiments of music and had also received their vocal training in the sight singing classes. Every musician was a singer as a matter of course. Musical culture gradually spread from the church and began to embrace a wider field. During the 15th and the 16th centuries there was a steady approximation of the two orders of music, scholarly and popular. Every little royal and princely court had its retinue of musicians. Polyphonic music had reached a degree of development where its beauty brought it within the reach of the enjoyment of the great mass of the people.