Polyphony or Homophony for a synth noob

#1

I read a lot of posts making reference to Polyphony, which in general from my guitar based background are 2 or more sounds completely separate in melody and rhythm playing over the top of each other, as I would expect and what appears noticeable when reading posts, there are varying degrees of this. Not a common activity in a 4 piece rock band. However doing this with a synthesizer seams far more common in practice.

I listen to a lot of the posted examples within the forums, many of which do not appear to have a melody or a rhythm, so I can only imagine these use polyphony ?

Is there a general approach in recognizing whether a Polyphonic or Homophonic approach is being used within pieces ?

One of my reasons for this, is to improve my understanding of objects and topics with the Axo, and am also potentially looking at the possibility of a guitar melody triggering additional events at certain points, and so want to understand what is common to me in homophony where I can create patterns to loop and follow, or completely separated sounds where I can take inspiration from posts and performances on the forum.

Thanks..
:grin:

#2

As far as I can tell, polyphony in sound synthesis means that sound source is capable of producing more than one note/voice at a time. They don't neccesserily have to play different melody as it is normally understood in music theory. I.e. to play 3 notes chord you need 3 voice polyphony.

#3

Hey there,

Let's clarify the word polyphony for firstly:

Polyphony is usually described as 2 or more (poly means many) separate synthesizer voices ("phony") able to operate independently. You can have 2, 3, 4, and many more voices. Synthesizers or patches said to operate this way are described as being Polyphonic. A voice is usually considered a block of functionality that usually provides at the bare minimum on/off (gate) and note (frequency) controls. Often a synthesizer voice may have other parameters to be controlled as well. Synthesizers with many independent, but drastically different sounding parts, are called multitimbral (many sounds (timbres.)

I can imagine when you read about Axoloti patches here they're describing single patches that have many voices and form a complete instrument. A basic keyboard you may have played before (eg. an organ) would mimic this behavior.

To continue.. A synthesizer (or patch) that can only produce one unique sound at a time is considered to be monophonic. (mono meaning one) and phonic meaning voice or sound. I think you referred to them as homophonic - and sounds can be homophonic (2 or more sounds that sound the same) - but one voice/sound is called monophonic. There are many great monophonic synthesizers out there and they're the simplest form of a synthesizer to build and operate.

Generally you can recognize a polyphonic synthesizer patch by listening for chords - 2 or more notes that sound in harmony (similar to a guitar chord). You may hear a monophonic synthesizer sound by listening to voices sounding on their own - like a lead guitar solo.

These are only rules of thumb - simple ways to hear things - they may not be accurate in all cases.

Other words for you to investigate: paraphonic, multitimbral.

Check out wikipedia, youtube, or other syntheszier and electronic music forums for more resources.

#4

Thanks..
I know what most of the meanings are from a general overview, and certainly on line you can read a lot about differences to this meaning in particular, chords etc, as the general view is that only chords played in a certain way are considered polyphonic.
Anyhow, moving forward, I do like your comment regarding.

"A voice is usually considered a block of functionality that usually provides at the bare minimum on/off (gate) and note (frequency) controls. Often a synthesizer voice may have other parameters to be controlled as well. Synthesizers with many independent, but drastically different sounding parts, are called multitimbral (many sounds (timbres.) "

In some ways, these were the sort of references I was looking for, I think I need to read up a bit more in reference to Synth Voice, and will add paraphonic, multitimbral to the mix.

:slight_smile:

#5

When a synth is Paraphonic, it means you can play more than one note at a time but some of the functions of each voice are shared, usually envelopes or filters to save resources or expense. This can result in notes playing longer than they would independently, or a filter only tracking to the last note played. Multitimbral refers to an instrument that can play two or more sounds or patches simultaneously. Most often this is done by splitting the keyboard into two or more sections. An example would be a synth playing a bass patch below middle C and a lead above and including middle C.

A real world example of paraphonic, multitimbral synth would be the Electribe 2 groovebox from Korg. It has 16 parts each of which can play 4 notes but each shares a number of settings including filter and envelope. Realistically it can only play 8 to 10 parts at once. The Waldorf Blofeld is a desktop or keyboard synth that is polyphonic and multitimbral- each voice is independent.

And just to cover one more base, you might see some synths called 'Duophonic' and this is slightly different than implied. These synths can play two notes, but they do it by having two oscillators and assigning them to different keys, but only when two keys are pressed at once. The Korg Arp Odyssey (and the original) and some of the newer Moog synths do or can do this.

#6

Thanks for that @AxeBreaker ,
So if I review my understanding of all of this, its not always so much about whether something is monophonic or polyphonic, but also about achieving the required result with the equipment at hand.

I find interesting that you have, and is quite common is for references to types of synths, not being familiar with any of them, it is difficult to really understand why it is being referenced, but now it seams very clear that they way they function, can vary far more than I realized, and they are referenced because they take on an aspect of control that can be quite unique.

I know I might be stating the obvious, but digging deeper I am seeing this on the basis of the individual parts that create the uniqueness that one may try to emulate with an Axo and its available resources, and hence many words used that are in line with the concept.

:grin: