The documents of the Second Vatican Council mention two forms of music by name: Gregorian chant (which is, by definition in Latin) and "polyphony." Somehow I lived many years in the world of music without hearing it until one day when a friend suggested that I pick up a CD of Palestrina. I was astonished. This CD took over my life for weeks and months, and it started a massive change within me that gradually but decisively reconstructed my internal aesthetic. Quite simply, I didn't know polyphony was possible. Once I knew it was possible, I was never the same.
What is polyphony? It is music that employs several independent lines of music simultaneously but without using a dominant melody with accompaniment. It is usually choral music - though the contrapuntal technique also appears in instrumental works such as organ and piano music by Bach.
Usually the term is used to describe Church music of the Renaissance and after, but it is a mistake to indentify the style as somehow attached to a particular time. The style itself is timeless, and it is this way by design. The composers sought to bury the ego and try their best to present sounds that take us to eternity. No one living has "heard" eternity so we cannot know for sure, but if any music has rendered how our highest sense imagines eternity to sound like, it is polyphony.
It has been the pleasure of my adult life to be the conductor of a polyphonic choir, and this has been an amazing learning experience. There is massive variety in this genre but something wonderful to say about each piece. And the repertoire is voluminous to say that least. In fact, it is seemingly endless, encompassing thousands and tens of thousands of pieces of music - masterpieces that have been strangely overlooked by the mainstream that wrongly believes that all great music began with Bach.
In my years of experience with this, I've noted five aspects of polyphony that make it special and completely unlike other forms of familiar music. Maybe listing these features will help capture some of what makes this music great.
1. There is no master/slave relationship. In modern music, by which I mean mainstream music from the 17th century all the way up to the material you hear on radio today, there is a melody and accompaniment. Everyone who has take a piano lesson or looked at a score or a conventional hymn understands this. The is a main voice that carries the theme, usually the soprano part. Everyone else is there to support and otherwise adorn the theme. That is to say, there is a master, and everything else that happens is the slave.
In polyphony, no single voice dominates. Each part is important to the creation of the overall effect. You could say that that music is radically democratic, or socialistic, or egalitarian, perhaps individualistic, or orderly like the heavens, or all the above. I would say that the independence of lines, combined with their capacity for a mystical kind of integration, creates something like the perfect musical society - a utopia made of notes. Or you could say it is heavenly. In any case, on earth, there is always oligarchy and structures of authority. In polyphonic music, the angles are the voices so of course we have something completely different.
2. There is a beat but you don't hear it. And what a relief this is. For hundreds of years, music has been all about the beat. In popular music of all styles, the beat is the main structure, an indispensible part. In polyphony, the pulse is underneath everything that is going on but no one makes the sound and no one hears it except in the heart. It is possible to imagine the beat and grove to it but it is never quite audible. Nor do you want it to be audible. The music isn't missing anything without it, and with it, the music would not be enhanced but diminished. Moreover, most singers do not entirely realize this, but in modern music with accompaniment, the beat is provided be external instruments (not even the conductor). In polyphony, it comes from within and there is no other way to accomplished the musical task at hand.
3. Each part moves independently. In modern music, the dynamics (loud and soft) and pacing (fast and slow) all move together, so conductors direct as if this were always true. This goes for most everything between Mozart and Snoop Dogg. Not so with polyphony. As a conductor, it took me a long time to figure this out, but each section or singer has to figure out how the individual phrase rises and falls and render it that way regardless of what everyone else is doing. You really must try to think of your own line as a separate piece of music, while considering the way it integrates with other parts only for purposes of music and textual blend. The structure of the music takes care of the rest of it. I know of no modern style that so consistently demands this of musicians.
4. You can't really conduct it, so it is really music without a dictator. Most polyphony has entrances all over the place, and the conductor loses the ability to cue people to come in except on rare occasions. Even then, it isn't really possible to be a great master telling everyone what to do. There are too many moving parts. The singers have to learn to cue themselves and to think on their own. In actual fact, the most the director can do is keep a beat, and guard entrances and exits, and, even here, if the singers have internalized a pulse, the conductor can stop giving the beat. That leaves entrances and cutoffs, but this can often be handled with the smallest motions of breathing, eventually eliminating the need for someone to stand in front of the choir. Indeed, the more I conduct polyphony, the less I'm needed at all. Mostly these days, I like to stand with the singers and not move at all. This is a wonderful thing to behold: music whose only maestro is invisible.
5. It can be sung by a choir of any size. The typical renaissance choir had between four and eight singers. This might lead you to believe that this is the most that this music can handle. It is not true. I've sung Palestrina and Victoria and Isaac without 250 singers and it is all the most spectacular - I wouldn't say it is greater that way necessarily but it is entirely possible. To use a software term, this music is scalable: it can be reduced or expanded based on your existing forces of singers, however many their might be. It also scalable horizontally too. It was popular also during the high middles ages to write polyphony for 12, 28, or even 48 parts, and this is fantastic too. Or you can write it for only 2 parts. There is a beautiful simplicity to this. Or in the case of Byrd, whether it is for 3,4, or 5 parts, and the human ear can't always detect how many there are. This is because of the complexity of writing but it is also because the form and style are so flexible and beautiful.
Those are my five reasons for why I love polyphony and find it so great. There are additional considerations: such as how the music evolved from chant, how it effortless floats like incense, how nothing else sounds so much like Church, and more. But I'll leave it there, and urge readers who have never experienced this music to look into it further. This music is out of this world.