Dave:

Short answer, you can’t do what you are trying to do directly. Let me explain.

On the Montage, you can run in one of two different midi modes: SINGLE or MULTI. In SINGLE mode, the Montage receives MIDI data on a single channel that you specify (so all parts respond to that channel). In MULTI mode, Part 1 receives on Channel 1, Part 2 receives on Channel 2, Part 3 receives on Channel 3 and so on up to Part 16. This is a design choice made by Yamaha and personally I think it’s fine, but many have voiced their opinions about this in the forums.

To do what you want, you have do some midi routing (I believe your SL88 is a 4 Zone controller). First make sure the Montage is in MULTI mode. Then what you can do within most popular DAWs is setup MIDI tracks to receive from one device and Channel and output to a different Device on any channel you want. I’m not a Logic user so I can’t walk you through it step by step. But in concept, you’d setup a MIDI track for each part you want to control on the Montage. Input would be your SL88 on wantever channel you want, output would be Montage on the Channel for the Part you want to control (ie channel 2 for Part 2 etc). Make sure that all your tracks are armed and it should work.

Jeff

Is there a way I could assign a different midi channel to a part on the Montage like parts 1,2,3 -> midi channel 1, parts 4,5 -> midi channel 2 etc?

No.

is there a way to trick the Montage to send its part to whatever midi channel by using a software on a Mac.

The MONTAGE does not “send its part”... what do you mean here, perhaps you are talking about “Receive”. When the MONTAGE is the Slave device it Sends nothing, your Controller is Master, it is sending. So the question makes no sense.

I am thinking here maybe setting up something in the environment in Logic Pro X or use a software that would allow to match any of the first 8 parts of a performance to whatever midi channel we want.

No, that’s why you wanted it to be something you could solve by *Sending*... to find a solution. The issue is in reception, not sending.

You already know the MONTAGE has fixed Receive Channel for its Parts.
You already know your controller does not send on enough MIDI channels to trigger eight Parts.

Sorry, no, the MONTAGE when set to MIDI I/O Mode = Multi, each Part Receives on the MIDI Channel, 1-16, that matches the Part’s Number.
This MIDI I/O Mode = Multi, Sets the MONTAGE so that it Outputs a unique stream of MIDI events for each Part... this makes sense when you wish to record and then playback data generated by the MONTAGE. That’s the ‘prime directive’ when it comes to any product outputting MIDI... so you’ll be able to perform on it and capture every nuance of your Performance when playing that data back.

You have a controller capable of controlling just four MONTAGE Parts, simultaneously... when MIDI I/O Mode = Multi.

If you change the MONTAGE to MIDI I/O Mode = Single... this will allow you to play as many as eight MONTAGE Parts on a single MIDI Channel from your controller, you do so by activating the KBD CTRL on the Parts you wish to play simultaneously, while selecting the MIDI I/O Mode Single Channel to match your master controller’s Transmit channel.

To understand how the MIDI I/O Mode = Single works... is to appreciate that to play MONTAGE you physically have only one Keyboard - what goes out via MIDI in this mode is just the one stream of MIDI data that is generated by the one Keyboard. The main difference here is that the eight Arpeggiators do NOT output the Arp Phrase data when MIDI I/O = Single (obviously). I say obviously but it does become obvious when you realize that Drum Arps sound silly on the piano sound and vice versa! Lol.

When playing as many as eight Parts from a MONTAGE Performance, you are typically not directly playing them all simultaneously. Typically, some are triggered directly via your key presses, others are under control of an Arpeggiator (there are eight), and certainly it would be rare that all eight are sounding simultaneously... you are morphing between instruments sounds or transitioning through various combinations. Let’s call this “intelligent merging” of Parts. This is why discreet communication with each Part is required. And the reason for the massive MONTAGE control matrix.

In “non-intelligent merging” of Parts (simple splitting/layering) it’s probably okay to just have all Parts on the same MIDI Channel... when you increase volume or Pan or open the filter, they all do the same thing TOGETHER. MONTAGE’s design is the antithesis of that... when you move a Control each Part is addressed separately so with a single gesture I can turn the volume up on one Part, down on another, a lot on the next, not at all on the next, just a little on the next, etc., I can address panning individually for each, I can control the filters individually and specifically, even when scores of filters are involved! They do not all *have to* do the same thing.

What you can do is use the MONTAGE keys to play the KBD CTRL Parts... and your external controller to trigger four non-KBD CTRL Parts on any four MIDI channels of your choosing. Example, since you know the MONTAGE addresses Parts 1-8 for itself (KBD CTRL), you could use Parts 9-16 to setup your external controller... obviously the max it can do is four.

If you want a perfect external controller for MONTAGE, look at devices with eight Zones. Otherwise, limit your external control options to the number your master Keyboard allows simultaneously, four.

If you choose to use the external controller for its weighted action, presumably for acoustic piano, the acoustic piano sounds on MONTAGE are all four Parts or less.

See the following:
MONTAGE MIDI: Zone Master FAQ
MONTAGE MIDI: Zone Master and MIDI I/O Modes

Other options include learning to program your own Performances, ones that respond to how you would like perform... those who abandon trying never get the results they need. What, exactly, is your requirement? I ask that because consider that there might be a more “intelligent” approach to combining sounds than the ‘old method’ of stacking them on the same Receive Channel. I cannot promise it will get you results you desire, but at least you will have made the attempt to discover what’s NEW about MONTAGE. We truly believe the future of music performing (and MIDI) lies in the expansion of the multiple channel control arena.

Let us know.