I'm fairly knowledgeable about polyphony and texture
However, I don't understand why you would need 16 MIDI ports? You're not playing all 16 instruments at once? You'll only be playing one or two at most surely?
Most DAWs can playback up to 64 tracks at anyone time and that will be through your sound card, be it internal or external.
I'm failing to see how you can justify these requirements unless I'm missing something.
That reply also mans that actually you are NOT as fairly knowledgable as you would like to think.
Ok, a little more specific then....
I am writing a simple song...
This consists of
1 - Drums
2 - Bass
3 - Rhythm Guitar
4 - Lead guitar
Right, so, lead guitars take up 2 or 3 polynotes per note played, and if you play a simple strum of the guitar goinfg across all 6 strings... Bingo, thats 6x2 or 6x3 depending on the type of guitar... Single accousic guitars are only one of course but processed Lead Electric / distorted guitars for example can take 2 or 3.
The drums likes I sad can take up a lot more than you think when you hit the crash then a ride and these are both still ringing and faing out, you get back on to the kick & Snare and tap the hats and then rolling the toms... If each sound from each piece of the kit is still playing out ( as it shoud do for a realistic drum sound ) you can easily go over a 6 note polyphony
We can clearly see that we can go way over a polyphony of 16 on just guitars and drums
Or do you still need more?
(( I only need one or two? ))
Ok, so each instrument only needs one channel. This is true yes. However, Drums being one, Bass bring a second, Lead Guitar a third...
For a lot music, sure, you only really need 4 or 5 and I will be honest with you, but you do tend to use them up a lot quicker than you think.
Like I said previously some of my hardware sounds different to others, and sometimes I might like to use, lets say the Jazz Drumkit from the Korg, but I mighjt like the Electronic toms from the Brush kit on the GMega, I might also want to use some special effects on the Jazz kit on some sounds on the Korg, but not on others, lets say I want the Kick & Snare to be crisp and clean, but the hats to be heaily effected, with say a lot of chorus.
Now that lot would require me to use 2 channels on the Korg, and a Third channel on the Kawai GMega... Thats only for the percussions.
I might also want to add some echo-ish sound to a Guitar solo... Maybe a half second delay for example...
Well, the simplest way to acheive this, is simply to copy the track, or the pattern section of the bit I want to have the effect on, and I simply copy & paste the section, and then shift that part over by whatever.
Bingo, I have just taken up 2 channels on that too!
Sure, I could perhaps point both tracks to the one channel, and this will work fiune for most sound Modules / Keyboards except for one small issue... It does not always happen, but some kit of mine it does, but Midi works by switching a note on and off at a certain volume right...
Well in this example, the keyboard might get a NOTE ON command and then half a second later it will get the NOTE ON ... It knows the note is on and it put it on again... It then gets a NOTE OFF comand and it stops the note dead. Now we could have 2 problems here... It might also cut off the echoed sound, of, when it received the second NOTE OFF command, it might think the note is off and not bother doing anything, and we end up with a hung note that wont stop.
Also we might want to effect the echoed sound differently to the main sound, and we can only do that if the main sound is on a different channel to the echoed sound.
Can you see where I am going here?
Not only this, but another example of using more than one channel even for the exact same sound, is for panning the voice over.
you can pan a channel to anywhere, the values are 0 for far left and 127 for far right, with 64 being the middlle
Now, you can set this to anywhere you like in that range at any time you like, you can also have it so teh sound flies around left to right, to right to left and so on... Its a nice effect.
Now,You might also want to add a really nice effect, that I think works great, and that is to have the lower / bass sounds of an instrument ( Pianos are the best for this ) playing down on the far left, and the higher up the piano you go, the further to the right the sound.
A basic example is that keys from Middle C and down, all play to the left-ish or PANNED to 32 and the Keys above middle C, panned to the right, or PANNED to 96
When you have headphones it makes a nice effect.
This requires 2 channels just on the Piano.
You could go a little more OTT and set up a channel for each octave too, and sure, I ahve done this and its completely silly and wasteful, but it makes it worthwhile... It takes up 8 channels on an 8 octave piece, but it also makes it sound brilliant. Its an effect that is built in on high end kit but not on lower end stuff ( usually ) and so, can you now see how I can need more than 2 or 3 channels?
There are other tricks also to lowering the number of channels used...
Even if I use all 16 channels, they are rarely all being used all at the same time.
I might have a peice that hasa nice guitar solo, and then a chorus, and then a Saxaphone perhaps and then the chorus and back to the guitar, and sure, the guitar and the sax could both share track X and as long as I put in the parameter values / sysex / effects etc in teh right places and as long as I dont need them to both play, then I will be fine, but why should I? one channel for each bit
Surely now you can see where I am coming from?
As another thing to consider... Why do professional recording studios have massive multitrack recorders and mixers? - its no different to twonks like me... We do need them even if we dont use them all the time.