"Out of the box" Montage is configured and acts differently than Motif with respect to MIDI channels and response of Parts. At least in the default resting states of each.

First, let me say that absolutely Cubase AI (I tested Cubase AI 9.5) can trigger any arpeggio(s) on Montage. They are not blocked. Having arpeggios not seem to work would be a matter of configuration.

Some key questions to know answers to:

1) Is your keyboard in Multi-Channel, Single-Channel, Hybrid - MIDI mode? You will notice that setting to single-channel MIDI mode (and also setting the receive/transmit channel correctly) will result in a more familiar response. Although this is not the answer - a clue as to what's different.

2) What MIDI channel is Cubase sending its MIDI out? You get choices of 1-16 or All. For now, I would choose a specific numbered MIDI channel. If your keyboard is in Multi-Channel MIDI mode (which is the default) - then the MIDI channel you send out from Cubase will target the Part number that corresponds. Midi Channel 1 = Part 1. Midi Channel 8 = Part 8. And so on.

3) Which Part(s) has the Arpeggio(s) you want to target?

... there's also the normal Motif-era questions to know answers to. What are the Arp note and velocity limits? What's the mode (direct, thru, sort, etc)?

Here's what I did:

1) On Montage recalled the "DJ Montage" preset Performance
2) Edited Part 8's arpeggio to turn off arpeggio Hold. I did this just so I could stop sending note on events and the drums would stop. Part 8 are the drums.
3) Set the Scene # by pressing the blue scene button to Scene # 3.
4) Plugged in Montage to my computer with USB cable. Setup was Multi-Channel USB mode.
5) Loaded Cubase AI 9.5 on PC. Opened a new blank project. Added one MIDI track. Set the MIDI track output to MIDI Channel 1
6) Added a whole note on Cubase's C3 (middle C) using the score editor
7) Turned cycle on to repeat (over and over) the first measure - which repeated pressing "C3" for a measure.
8) Pressed "play" on Cubase's transport controls to start hearing Montage play the cycle.

Now ...

With Cubase's MIDI track MIDI output channel 1 - I hear a higher pitched sound (ARP pattern). Almost like an eastern stringed instrument.
With Cubase's MIDI track MIDI output channel 2 - I didn't hear any sound
With Cubase's MIDI track MIDI output channel 3 - I didn't hear any sound
With Cubase's MIDI track MIDI output channel 4 - I didn't hear any sound
With Cubase's MIDI track MIDI output channel 5 - I hear a synth sound (ARP pattern)
With Cubase's MIDI track MIDI output channel 6 - I hear a soft pad sound (note: this Part isn't running an ARP - so I just hear the pad sound held with the whole note C3)
With Cubase's MIDI track MIDI output channel 7 - I hear a bass ARP pattern
With Cubase's MIDI track MIDI output channel 8 - I hear the drums

And to hear it all together, what I did was I took my MIDI track and duplicated it 4 times then changed each of the 5 MIDI output channels so they were: 1, 5, 6, 7, 8. One of these different channels for each track. Although I added Part 6 - this is the odd man out. Part 6 isn't running an ARP. However, it still contributes to the overall sound so I added it.

I would actually duplicate to 8 MIDI tracks and target each MIDI channel 1-8 to cover all of the DJ Montage Parts. And all except Part 6 (1,2,3,4,5,7,8) to cover just the ARP parts of DJ Montage.

The other way to get here, as mentioned near the top, is to change Montage to single-channel, set the I/O channel to Ch 1 (or your favorite) then make Cubase's MIDI out channel for the MIDI track to Ch 1 (or the favorite you picked).

Hello Dear jason

The settings that you mentioned in the beginning are correct (about muti chanel etc...)

The sending chords to MONTAGE from Cubase via MIDI are activating the arpegiator !

The arpegiator is blocked every time I activate the >> UTILITY>>SETTINGS>>MIDI I/O >> (Arp MIDI Out) option fron OFF >> to >> ON.
I want the input MIDI chords from Chanel 01 to be reproduced by arpegiator and recorded in chanel 02 for example, and this is possible only if I turn ON the (Arp MIDI Out) option.

If I play on the keyboard, the apregiator is sending data to the chanel 02 but if I try to do the same via Cubase the arperiator is blocked !

If I do not turn ON the (Arp MIDI Out) then the arpegiator is not blocked!

I hope that I was more detailed this time.

Thanks a lot!

With "ARP MIDI Out" off - you will see the notes you used to trigger the ARP on MIDI out.

With "ARP MIDI Out" on - you will see the notes that the ARP is playing (not the notes you are using to trigger the ARP).

I'm not sure what this happens to do with making something on Channel/Part 1 show up on Channel/Part 2.

If you have an ARP on Part 2 and you're in Multi-Part MIDI mode then you need to send the chords to Part 2 so Part 2's arpeggiator can get triggered. It doesn't happen automatically just because you turn "ARP MIDI Out" on or off.

So with "ARP MIDI Out" turned on - you'll see the result of an ARP pattern. While if it is turned off (ARP MIDI Out) - then you will see your trigger notes and NOT the result of the ARP pattern. The reason for this is that you may want to document the trigger notes so you can later trigger the ARP in the same manner and not document all of the notes the ARP outputs.