Hello Everybody,
 
I would like to know if anybody knows how I can make micro-tonal changes in the midi notes. I want to be able to get pure thirds, experiment with neutral thirds and other notes as well. I want to be able to do this on a note by note basis sometimes having one type of value for a third or seventh, sometimes another. Thanks in advance,
 
Mark

Microtuning usually depends on the capability of the softsynth to respond to midi tuning data. Many simply do not have that capability, but there are some programs that will supposedly translate microtuning scales to pitch bend events and so control synths that are not designed to allow microtuing. Most of the time you would be using a scale file to define a scale that the synth would play. If you want to switch tunings from note to note, you would probably have to hand code the events, or split the midi into multiple tracks to address synths with the different tuning scales.
 
This is not simple stuff that can be explained in a few words on a forum but, you can start with these resources:
 
http://www.xen-arts.com/p/xen-articles.html
http://www.huygens-fokker.org/scala/
 

A Scala-enabled synth would be the way to go, as the pitch bend events can get cumbersome and data-intensive.  In Sonar / Cakewalk, you can start with Dimension Pro, Rapture & z3ta+ (or z3ta+ 2.1).  The Scala application for creating files appears daunting, but it's not that difficult once you get your head wrapped around the basics.  Save the generated text files with an *.scl file extension into one of those synths' Tuning folders, and they will be available for use on the next instantiation.

I want to be able to do this on a note by note basis sometimes having one type of value for a third or seventh, sometimes another.

I'd use Rapture for this.  It has six Elements [a complete synth in itself], and each Element can load its own unique Scala file.  You could copy/paste a nearly identical synth configuration into each Element, a different Scala variation in each, then switch among them.  Might be easiest to use Multitimbral mode, and change the note values from MIDI Channels 1-6.

Thank you both for your quick replies! I will look into the resources slartabartfast provided and the scala solution you both recommend. Thanks for letting me know that Rapture is capable of reading the Scala files.
 
I did find the website below that has resources and two octave 422 key two octave controllers for sale. I can not afford one at the moment though, and from what you both are saying, not every synth is capable of receiving microtonal pitch information. Thanks again for the info, you all have been a big help. 
 
Time to learn Scala programming. 
 
Insane 422 key two octave midi controller. 
http://www.h-pi.com/index.html

I would be inclined to try it this way using Rapture (or possibly DimPro). Load the first Element with the instrument that you wish to use. Copy and past the first Element settings to all the other Elements. Set to Multitimbral. Set the pitch of Element 2 to -14 cents to represent a major third. Similarly set the other Elements 3 & 4 to +14 & -31 cents to represent sixth and seventh intervals.  Use Elements 5 & 6 for other intervals if you wish.
 

You can use pitch bend to raise or lower a note's pitch in cents.
There are 100 cents in a half-step.  Use a calculator to convert MIDI pitch bend controller values (-8192 to +8192) into cents. 
 
Let's say to raise a pitch one octave requires Pitch Bend = 8192 (also depends upon to which interval your pitch bend wheel is set to move to when at maximum).
 
So if 8192 is 1 octave, then one semitone is 1/12 of 8192, or 683 (rounded off) .
 
If you want to change an interval by a 10th of a semitone, use 68 or -68.  To raise or lower by a quarter tone, use + or - 342, and so on.
 
Jerry
www.jerrygerber.com
 
 

Thanks Everybody, I might try the pitch bend as it sounds like I would run out of elements pretty quick. I am wanting to build some 7 note poly chords with these intervals by stacking them. It's almost more for my own research and amusement purposes at this point. For instance, stacking the Lydian scale (in thirds) using 5/4 as the major third ratio vs 81/64 as the M3 yields a slightly different sound, while always keeping the P5 at 702. I calculate the minor third interval by always subtracting what ever cents the Major third I choose is, from 702 so that the minor third and major third will always yield 702 regardless of what ratio I use for the third. Some of the charts I have have decimals for the cents, so having a resolution of 683 per semitone would get pretty exact. Of course, I don't think I can even hear the difference of a couple of cents, but if I am stacking up 7 note chords they will slowly add up. Thanks again everybody.

I've had some experience dealing with pitch bend info using midi guitar systems.
 
The Roland GR-33 played well on its internal synth but didn't translate to VSTi's because some notes were written as a lower note bent up a half step etc. That's fine if your synths use the same pitch bend range. So like on a keyboard when you push the pitch wheel all the way up it could be set to move from 2-24 semi tones, that's the range. Some VSTi's (like slynth) can be changed, some can't.
 
With pitch bend, you're bending everything you send it, so you would have a hard time dropping this note 7 cents and that note 2 cents etc. unless they're played sequentially with their own pitch bend info.
 
I think it stays bent until you send it another messeage to go back to 0, so it could be pretty easy to put in a message at the beggining and drop everything that follows by a set amount.
 
Best I can remember...
 

I want to thank all involved. I had no idea.

I'll be curious to hear the progress with the per-note pitch bend experiments.  We've all heard the zippering noise from synths that only process a pitch bend's MSB (setting the LSB to 0).  MIDI controllers often cheap out to 128 values.  I'm lucky to have some 12-bit resolution pitch wheels here, and I suppose one would pay dearly for full 14-bit wheel resolution.
 
There's also a tendency in DAWs to round out the pitch bend values with draw tools; sometimes severely.  Something as precise as the OP is looking for almost demands using the Event List View.  I've been toying around with a few experiments there, using a live input MIDI controller with Channel Aftertouch.
 
Now the AT is going to generate excessive events, but at least they closely follow each note on event.  I select the second aftertouch in the Event List after a note, repeatedly delete the extraneous, and convert the remaining first aftertouch message to a Wheel event.  That PB message value carries over to the next note on event.
 
A little tedious, but precise.