Jack
For switching between parts within the same performance you can use the super knob to fade one part in and at the same time fade another part out. The super knob can also be controller with a foot controller like Yamaha fc7 so you don't even need to take your hands off to switch sounds.

Bad mister has written some great tutorials on the super knob on this site and he describes how to fade between parts.

cheers ! Sean .,Super knob has to set for each tone change isn't it?it has great features but I don't know this is the only part finding hard.I had Fantom G6 , Korg trition extream ,in these i can change the tones on the spot without any delays.I wonder why couldn't do this on montage .

The super knob setting would have to be set up like this for each performance you want to switch like this. Once you get the hang of it setting this up for a performance doesn't take long.

There are other ways of doing it like using the mute buttons to mute certain parts or setting up scenes with different volume settings for each part.

@Jack, you are completely unnecessarily opening another thread with the same question. I will ask you again. Are you on the latest OS? You ignored my question but some very early Montage models had a problem with what you call delay.

Sorry I did not ignore your answer.I have already updated.but the result it same.

My suggestion stands. Use scenes to mute and unmute PARTs. This is the fast switch method. Your stated methods were the slower methods which have their place and more details about that were previously given.

Avail yourself to tutorials and videos on scenes as your homework.

At some point you may want sounds you are holding not to "cut off" abruptly when switching scenes. Something to replicate SSS in the context of a single Performance. That is where you would employ XA and is something to work on after getting scene programming under your belt.

Hey here's another method that allows seamless switching between parts with no delay and allows notes from previously selected parts to sustain/release without being cut off by using the scene method.

1) Turn off keyboard control for all parts in the Performance.
2) now, whichever part you select (either on touch screen or by the part select buttons) will be triggered by the keyboard and previously selected part will continue sustaining (if notes are still being held or if pedal is down) or will be allowed to fade to zero volume using its release time value. (No hard cut)

Try it out! 🙂

Jason and Joe thank you I'm going try all these methods

Joe's method works fine - I personally do not use that method because I rarely have one PART playing at a time. Often I switch in/out more than one PART at a time or otherwise have two (or more) PARTs active at any given scene location. The keyboard control method only allows for one PART at a time. If that limitation is acceptable - then that would actually be preferable due to the inherent "seamless" nature of transitioning between PARTs. Also, less of a consideration - but something I would grapple with in using keyboard control - is where the buttons and controls are for that method. Either touch-screen (which I do not like to fiddle with in the middle of a song) or buttons located on the right-hand side of the keyboard. My "free" hand during performance is my left 9-out-of-10 times for pressing buttons. Invoking selecting PARTs to transition in keyboard control=off would have me either cross-over the control surface with my left hand - or force right-hand non-piano-key-button-mashing. My current button-mash "dance" isn't choreographed for right-hand gestures. As mentioned, it's less of a consideration. You can probably learn where to sneak in right-hand button mashing or cross over with the left.

Incidentally, I believe there's an Init preset which sets up the keyboard with keyboard control=off for most PARTs (except PART1). "Init Multi/GM". It may be easier for you to setup your own Performance with PARTs in the traditional manner and just use the touch-screen to turn off keyboard control instead of using "Init Multi/GM" as a starting point. Several ways to skin this cat.