N.

 1 15|  beginning in the 9th century, polyphonic singing was added to this
 2 15|    chant. The study and use of polyphonic singing were developed more
 3 16|        Church always held this polyphonic chant in the highest esteem,
 4 54|        chant to exclude sacred polyphonic music from the rites of
 5 54|   rites of the Church. If this polyphonic music is endowed with the
 6 54|      certainly knows that many polyphonic compositions, especially
 7 55|       of the centuries genuine polyphonic art gradually declined and
 8 56|        the old masters and the polyphonic compositions of more recent
 9 56| simpler but genuinely artistic polyphonic compositions are often sung
10 58|        to keep out of churches polyphonic music which, because of