There’s a reason Gregorian chants were so big back in the day. First, these songs were one-note-at-a-time vocal affairs, the kind of music that sounded good and holy with the acoustics of Gothic cathedrals. The effect the architectural structure of those old churches had on music–the natural echo, reverb and decay of sound–was significant and profound. The only way the notes could be kept from overlapping and interfering with each other was to space them out in single, slow, carefully measured intervals. Second, the clergy believe that one note at a time was plenty for everyone.
But then some weirdo liberal musicians–aren’t they all?–tried to slip polyphonic music into church in the 13th and 14th century. Instead of basic one-note-at-a-time chants, this new music began to feature more than one instrument, adding chords, counter-melodies and harmonies.
This caused a scandal. The clergy was outraged to the point where Pope John XXII issued a ban on polyphonic melodies. His reasoning? “They intoxicate the ear without satisfying it” and create “a sensuous and indecent atmosphere” during the liturgy. This band on “lascivious, impure” polyphonic music stayed in place until the mid 1500s.
It took the performance of a piece called “Missa Papae Marcielli” by a dude named Palestrina to change everyone’s mind. It helped that this musical Mass was written in honour of Pope Marellus II. He really dug it, declaring it too beautiful to be kept from the people of The Church. Suddenly the ban was lifted. Weird how that happened, huh?