I'm still a little confused. Here's my current understanding of the situation: The channels that you assign to the insts. on your multitimbral synths do matter as they are linked to your tracks, right? So, you output your flute track to the channel on your synth that is your flute. I always put that on channel. I put oboes on 2, and so on. Each inst. track is output-ed to one of the 16 slots in my synth, corresponding to the insts. I have loaded. The result is all my insts. play the tracks/notes assigned to them. I can also play each inst with my midi keyboard, and record midi as well. So, the channels we are talking about here do matter, right?
 
The channels that I don't think matter are the ones listed in the Event List (EL). Each note and CC event in the EL will have a channel number. In Sonar, those numbers always stay the same for a given inst, regardless of what you do. You can copy from one inst to another, drag notes from one to another, and in Sonar, the channels "don't follow." The channels will change to the new inst's channel assignment. So, I move a flute part to the oboes, the channels in the oboe's EL will be 2, not 1 (the channel for the flutes - keeping with the example above.).
 
In Reaper however, things are different. When you move notes from one inst to another, the channels do follow, so the flute part I move to the oboe will still have channel 1 in the EL. Making me think that I need to change them, as those notes now are on the oboe. But if I'm understanding Bruce correctly, no, it's a waste of time, they don't matter, they are overridden by the routing assignments. 
 
Is this what you're saying, Bruce? 
 
 
 
 

michael diemer
I'm still a little confused. Here's my current understanding of the situation: The channels that you assign to the insts. on your multitimbral synths do matter as they are linked to your tracks, right? So, you output your flute track to the channel on your synth that is your flute. I always put that on channel. I put oboes on 2, and so on. Each inst. track is output-ed to one of the 16 slots in my synth, corresponding to the insts. I have loaded. The result is all my insts. play the tracks/notes assigned to them. I can also play each inst with my midi keyboard, and record midi as well. So, the channels we are talking about here do matter, right?

Yes - midi channels need to be assigned so that your tracks line up with your sounds.
 
 

michael diemer
 
The channels that I don't think matter are the ones listed in the Event List (EL). Each note and CC event in the EL will have a channel number. In Sonar, those numbers always stay the same for a given inst, regardless of what you do. You can copy from one inst to another, drag notes from one to another, and in Sonar, the channels "don't follow." The channels will change to the new inst's channel assignment. So, I move a flute part to the oboes, the channels in the oboe's EL will be 2, not 1 (the channel for the flutes - keeping with the example above.).
 

 
Right again Michael:)
 

michael diemer
 
In Reaper however, things are different. When you move notes from one inst to another, the channels do follow, so the flute part I move to the oboe will still have channel 1 in the EL. Making me think that I need to change them, as those notes now are on the oboe. But if I'm understanding Bruce correctly, no, it's a waste of time, they don't matter, they are overridden by the routing assignments. 
 
Is this what you're saying, Bruce? 
 

I dont use reaper, but they are overidden in Sonar and you never need to change them manually. If you save the project as a Cakewalk project, the midi notes remain as the channel number they were originally recorded on and the channel outputs override that as discussed. I just ran a quick export test (though I am on platinum). If you save the project in Sonar as a midi file (choose type1 in the dialogue), then close the project and open the midi file you just saved you will notice that all of the channel numbers HAVE changed to the respective channels they are on, so that irrepective of what program you open it in the channel assignments will be correct.
 
As far as exporting from Reaper it is simple to test. When you move parts from a track assigned to one sound to a track assigned to another, does it play the correct sound (ie, the instrument assigned to the new track) irrespective of what the event view lists? If so, without changing anything export the midi file and open it in Sonar. If the sounds show up on the correct tracks (irrespective of what the event viewer indicates about the individual notes) then all is well!
 

Thanks again Bruce, and great idea for the test. I'll give that a whirl and let you know. In the meantime, I have been ignoring the Event List channels, not changing them, and everything sounds normal.

You know on reflection I can see no logical reason Sonar shouldn't change those individual midi note channel numbers to the track midi channel output setting as soon as the data is moved or recorded onto a track. It would certainly make editing in the event list less confusing.

I thought Sonar did that, it's Reaper that doesn't. Or did you mean Reaper?

Let's simplify the discussion:
 
1.  Both SONAR and the other DAW you reference stores each MIDI event with the initial recorded channel or the channel that is found in the imported MIDI file.  This initial MIDI channel will display in the Event List or in the MIDI Properties dialog in both DAWs.
 
2.  When SONAR saves a MIDI file using File>Save As, it overwrites the stored MIDI event channel with any track channel assignment made in the Inspector unless the track channel is set to None.
 
3.  When File> Export Project MIDI is performed in the other DAW, it does not overwrite the stored MIDI event channel with the MIDI channel assigned in the Send/Receive dialog.
 
As everyone has stated, the MIDI channels in an imported MIDI file do not matter if the application that is playing the file allows you to reassign the channel of the track(s) containing the MIDI events through internal routing (i.e. the SONAR Inspector or the other DAW's Send/Receive dialog).
 
You only have to be concerned with the MIDI Event channel if the device or application that is playing the file cannot reassign track channels.  For example, I still have a Roland SoundBrush that plays MIDI files on a floppy disk and has no internal routing capabilities.
 
Hope this helps,
-- Ron
 
 

michael diemer
I thought Sonar did that, it's Reaper that doesn't. Or did you mean Reaper?

Sonar retains the original note channel number of the device it was recorded from unless you export the project as a midi file (remember - it is meaningless as it is overidden by the channel output setting of the Sonar track it is recorded onto, so there is no need to worry about it). My point is that it would be simpler from an event list point of view if it was given the channel number of the receiving tracks output setting immediately.

The MIDI spec was written when only real instruments were available for play, connected via a relatively slow serial protocol. In order to control multiple instruments the MIDI Thru protocol allows you to daisy chain multiple instruments along the same continuous connection. In order to define which instrument will play which note, the instrument/sound source is set to receive on a single channel. To avoid breaks in transmission by trying to send all of the notes for one instrument before sending notes intended for other instruments, it is necessary to interleave the note messages. And in order to activate the intended instrument it is necessary to label each note message with the destination channel. A dumb sequencer that just delivers sequential notes from a MIDI file needs to have the notes assigned to channel numbers in that situation. The channel messages in the data stream would appear in the event view or another MIDI parser with each note assigned to the appropriate channel.
 
A track based sequencer like SONAR can assign all of the notes to the individual track's channel, and then deliver them labeled with the appropriate channel as they are encountered (cross the now time) in playback creating the interleaved notes strung along the data stream to the MIDI cable on the fly. The output to the MIDI cable is going to have each note's channel label appropriately assigned in this situation. The advantage of having all of the notes in a given track assigned to the same channel are obvious in that situation, since editing any note in the track affects the same instrument, but everything gets sorted out when all tracks are played together as a mix. It is advantageous in that situation not to move the per note channel assignment from one track to another, since the effect of moving/copying a note to a different track is almost always because you want it played on a different instrument/output. For the same reason importing a MIDI file into a single track, as opposed to importing it into the sequencer as a whole and creating and splitting it into tracks based on their existing channel number, would generally be done because you intended all of the notes to be played from that single track to the assigned instrument. 
 
Within a given DAW the actual communication between the sequencer and the virtual instruments assigned to a track, while they may contain data in MIDI format for compatibility, are likely not being transmitted by the standard MIDI transfer protocol. Commands can be delivered orders of magnitude faster, and processed outside of the strict sequence that would be required to activate daisy chained real instruments.

Thanks slartabartfast. Great insight!

Thanks also Squire Ron., and double scoop to bart for the detailed history of midi, that really puts it in perspective. Like I said on another thread recently, the wisdom in this place is amazing. It's why I stay in touch. Sometimes problems arise that are generic across DAWS, and the knowledge base here is in a class by itself. Thanks so much, guys, you're the best.