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MIDI Polyphony and Multi-timbrality

Korg Oasys
Korg Oasys

What is Polyphony?

Polyphony is simply the number of notes that a keyboard or device can be playing at any one time. So, for example, if you press two keys at the same time, you’re using 2 notes of polyphony. Simple, right? Well… not exactly.

Another way to use two notes of polyphony would be to hold the sustain pedal and hit the same note twice in a row.

Additionally, playing a note in a “Combi” mode (where sounds are layered or stacked on each other to make rich tones) allows you to use up many polyphony notes with every single key press.

Polyphony is also used when running a sequencer or record function, playing a keyboard’s on-board drums, using the song or style arranger, etc.

So, you can see it is important to understand the ramification and how polyphony fits into your playing style and available equipment.

What is Multi-timbrality?

Being “multi-timbral” can be related to polyphony, but is actually the ability to play multiple types of sounds at the same time.  So, you want to play a bass line with the left hand and piano with the right? You’ll need multi-tembral capabilities in your keyboard.

Many times the different sounds are separated onto different MIDI channels and can be manipulated on a channel by channel basis. But often, as seen in many lower prices models, the keyboards are not multi-timbral and can only play one sound type at a time.

Obviously the more use you make of your keyboard’s multi-tembral features, the more available polyphony you will need.

Why should I care?

Polyphony is very important. The last thing you want to do is to get home with your wonderful new keyboard or sound module, start playing and discover it can only play 16 notes at a time. 16 note polyphony.  If you find that to be the case, you might as well throw your sustain pedal out the window. You won’t be using it.

It’s like this… you have 10 fingers. if each finger plays two notes (in a run or in repetitive strokes) and your polyphony is 16 notes, you’re 4 notes over the limit right away. The keyboard will start to shut off previous notes to compensate for the new ones.  Although sometimes it’s okay, this usually sounds bad and ruins your musical experience.

Some lower end keyboards can be in the 8 to 30 polyphony range (or less). Most higher end keyboards these days come in 64 to 128 note polyphony. This is pretty good for playing individual instruments that aren’t layered and many pad/synth or multi-layered sounds.  But if you’re going to be doing any major composing or orchestrating, you may likely need even more.

What can I do about it?

If you are stuck with a keyboard or sound module that has a low limit for polyphony or you find you are pushing the limits of what it can output, there are couple things you can do.

1. Get another sound unit. Purchase an additional sound module or keyboard and connect them using MIDI. This will double (or more) the polyphony available to you. Plus, it’s always fun to get new gear.

2. See if your sound module is expandable. Often you can buy cartridges or expansion chips that will increase the functionality of your existing device.

3. If you’re making complex arrangements and running out of notes, you may need to record some of your tracks into a computer, converting the notes into audio waveforms. This will allow you to shut those notes off in your arrangement and free up some polyphony.

If anyone has any suggestions, or more Polyphony tips, please comment below.

 

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Axis 64 Midi Controller

OK, I’m all for innovation and changing the way we do things for the better. So in the spirit of experimentation I thought I would post this cool MIDI controller I found online.

This guy, Peter Davies, redesigned the musical keyboard arranging the keys based on harmonic table.

Take a look. It’s pretty cool looking.

My initial thoughts are… what about velocity sensitivity and after touch. But these are issues that I’m sure could be addressed easily enough.

Let me know what you think of this device.
Do you like it?
Have you used it?
What are the drawbacks or benefits?

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Two Keyboards is like Four Keyboards

peavey dpm3
peavey dpm3

I remember in college when I bought my first two-tier keyboard stand. It was great. I was so excited. Now all I needed was the second keyboard. Of course being a penniless, starving student didn’t allow for the extravagance of purchasing excess gear. So I went for what seemed like a really long time with just one keyboard.

At the time I had a Peavey DPM3, which was actually way more keyboard than I knew what to do with. I was completely overwhelmed by the thought of oscillators and envelopes and filters and modulators. But one thing I did know was that I had 16 MIDI channels to work with and only one set of keys. And this was a limitation that I was determined to overcome.

Although I only owned one keyboard, I knew that if I could get my hands on another one I could “MIDI them together” to access way more sounds (using different MIDI channels) than I could play with just the one keyboard. For example, in performance mode I could layer 5 sounds using MIDI Channels 1-5 and play those all with the main keyboard. Then using a second keyboard as a controller I could access another bank of 5 sounds on channels 6-10 without ever needing to change patches. So even though I was playing the two sets of keys, I would only trigger the sounds from the main keyboard.

It gets better. Using this logic, I determined that I could also do the same for the second keyboard, and at the same time. I could make my ‘main’ keyboard access the ‘secondary’ keyboard’s sounds as well.

Kawai k1
Kawai k1

So, with much begging, threatening, and bribing, I convinced my brother to loan me his Kawai K1 for the weekend and I tried it.

Not only did my experiment work…. I looked SO COOL doing it! In fact, I think my wife married me because of this. (Ahhh… But that’s a story for another day)

By hooking the two keyboards together with MIDI, I was essentially using two sets of sounds from one and two sets of sounds from the other, at the same time. That’s why having two keyboards is actually like four keyboards.

SIDE NOTE: Using this logic… Three keyboards would be like having nine. I have yet to try that one.

What do you think? Do you have any interesting ‘MIDI Chaining” stories to tell?