Problem with external MIDI routing has to be MainStage 2 bug

Question

I posted a bug the other day where I was getting occasional bogus MIDI note events in one external synth while playing a keyboard that was (supposed to be only) sending MIDI data to a different external synth.
I have now performed two experiments that would seem to indicate that the problem must be caused by MainStage 2 and not by CoreMIDI or by MOTU drivers/external MIDI interfaces.
Experiment 1:
I created a new Digital Performer sequence, enabled multi-input mode and routed one keyboard controller to one external synth and another keyboard controller to another external synth, essentially reproducing the MainStage 2 patch. Played both keyboards together for some time with no problems whatsoever. (In MainStage 2, I'd get a glitch pretty quickly)
Experiment 2: (to eliminate the possibility that Digital Performer (a MOTU product itself) wasn't doing something special)
I used Max/MSP and created two midiin/midiout connections, one representing the first keyboard controller and external synth, the second representing the second keyboard controller and external synth respectively (duh). Again, I played both keyboards for a while and everything worked perfectly, no glitches.
I have reported this to Apple several times via their feedback but have heard NOTHING back from them.
Original bug posting
(http://discussions.apple.com/thread.jspa?threadID=2137282&tstart=0)

Answer 1

If I understand you correctly, I think I experienced a similar problem. However, in my case, I don't have two separate midi input devices, but rather one; and two separate external devices I am wanting to control with midi.
Brief background: I use an EWI to play various softsynths & now external synths via MS2. I also route the audio from my EWI into MS2 for additional processing and I use an external effects processor (Eventide Eclipse) for additional processing and sound manipulation. I send program changes with my EWI to change patches using MS2. My EWI transmits only on midi channel 1, which MS2 is set to receive on. Also, my Eclipse is set to receive midi data on channel 5 (a method I used to keep things separate in my all hardware rig when MOTU MTP AV was my switching device).
Initially, I thought I could just have my EWI send a program change message on channel 1, and then MS2 would send a program change message to the Eclipse on channel 5, all from the same MS2 keyboard object. It worked, but with one small glitch ... after the program change happened, and I started playing my EWI, the Eclipse began receiving my midi note information which in turn caused the Eclipse to be confused and start trying to change patches, etc. I checked the keyboard object which was not supposed to transmit on channel 1 to anything external, but I could not figure out how to set it up. Note: none of my devices are set to OMNI because I learned a long time ago, that I want to control routing and specific channels ensure their separation ... or supposed to anyway.
What I ended up doing was to create another midi object (this time the little spherical thing, not the keyboard), and assigned it to transmit on midi channel 5 and not receive on any channel. This turned out to be the solution / work around for this situation.
Another problem I am having with midi control when using MS2 as a go-between, is an issue with pitch bend information getting messed up as its sent to my external synth (Yamaha VL70m). For some reason, playing the VL70m by way of MS2, causes my EWI pitch-bend data to force the VL70m pitch-bend in the permanent down position making all notes flat. My solution in this case was to set up a direct link with MidiPipe, from my EWI to my VL70m and filter out any program changes so that I can use the MS2 to send a patch change to it, but use my EWI to play it directly. It seems to work well, and my pitch-bend is back to normal, but I am not certain (and don't know how to test) if the VL70m is now getting duplicate note on/off information with the potential of a minuscule delay from MS2 being in the path as opposed to playing direct from my EWI. It seems unnoticeable to my ears, but it's in the back of my mind.
Anyway, these are some of my midi episodes and I think it's pretty clear that Apple needs to quickly address some issues about midi handling and MS2.
Hope this helps ... and maybe we can come up with some more creative ways to deal with these "undocumented features" (to borrow a saying from the Windows world).