Transitioning what is sounding via the [SCENE] buttons is not guaranteed to be seamless. What determines if it is or not is exactly how you create the transition. As you may know there are several ways to do most things on a MONTAGE.

If you are using the [MUTE] function to turn On and Off the Parts involved the transition will be made by cutting the audio from reaching the Output on the active Part and connecting audio on the newly activated Part. Because this works like a “mute”, it will not provide a seamless transition.

If, however, you use the new KBD CTRL On/Off function that can be captured in a Scene, then the transition will be sonically invisible. This works by changing what gets transmitted by the Keyboard, (not what is routed to the outputs). The currently sounding Part will not be cut off when you activate the new Scene, (it will simply add no new notes from this point on), and all subsequent notes will play from the newly activated Part. This accomplishes a seamless transition between the Parts with cutting off the audio signal path.

When the KBD CTRL icon is green you are set to play that Part or set of Parts as a grouping. The condition of the KBD CTRL status can be memorized per Scene.. KBD CTRL can be set to any Part or group of Parts 1-8.

From the HOME screen
Touch “Scene” in the first column.
Changes made on this SCENE MEMORY screen are immediately activated.

First, make both of the Parts active by removing any Mutes you may have been using (mutes cut the sound).
Turn the MEMORY Switch for KBD CTRL = On
Mark the Part (KBD CTRL) you want to sound in this Scene 1, for example Part 1

Select Scene 2
Make sure both Parts are not Muted...
Turn the MEMORY Switch for KBD CTRL = On
Mark the Part (KBD CTRL) you want to sound in this Scene 2, for example Part 2

Now when performing switching from Scene 1 to Scene 2 will transition without cutting off the sound,

New with firmware 3.00 you can transition Parts using KBD CTRL

Thanks BM.

Extra Credit:
Understand [MUTE] buttons as a function of the built-in digital mixer.
Understand KBD CTRL as a function of the musical instrument.

[MUTE] is operated by the sound engineer... and disconnects/connects audio to an output
KBD CTRL is operated by the musician... and is all about your musical input being transmitted

When doing masterclasses on Synthesis, I often break down the MONTAGE/MODX as combining a digital mixer with a digital synthesizer. You wear two hats when you operate it; one is an engineer’s hat (where you make technical decisions) and the other is the musician’s hat (where your musical skills are used).

Muting a channel on the mixer is technical... changing how your keyboard transmits is musical.
Sometimes the line blurs, but in this instance it is clear.

Starting a Sequencer - is simply pressing a button (technical)
Starting an Arpeggio is musical, requires musical skills (you must play on the beat and exhibit chord quality recognition).

Operating the SLIDERS on the front panel is using the digital mixer, assigning and adjusting the output using the Super Knob system becomes a musical adjustment.
Adjusting playback Volume with the sliders is a technical decision, adjusting velocity to adjust volume is a musical decision.

Why it helps to think this way can be useful in gaining an understanding of how something may be designed to work. If you are performing, included in your musical performing gestures are ways to manipulate the resulting sound. When looking to transition instruments, some methods are designed to be sonically invisible, others are not. And this is usually On Purpose. In other words there are better and worse ways to accomplish things.

MUTEs work like they do for a very specific reason. A button that seamlessly transition from one sound to another is never called a “mute button”... that is not what a mute button does. It has another use, a specific use when you need to make abrupt changes, not changes made during sustaining notes, but at musical ‘breaks’. You don’t use a splice cut in a movie when you want a seamless transition. But that does not mean you’ll never need a splice cut. When you need one, nothing else will do.

And while we like to say there is no right or wrong when it comes to operation, using the [MUTE] button or memorizing Slider values for volume, when you want to transition between instruments undetected is, well, a poor choice. Using KBD CTRL, XA CONTROL, Super Knob assignments, are better (music friendly) choices.

Summary: once you are clear that the Mute button cuts off the sound by disconnecting the audio signal, you stop looking at it as a possible solution for seamless transitioning. You want to be able to play a sound and have it continue while you start playing another. This is a ‘musical decision’ that requires a solution, that does NOT disconnect or stop the audio signal. These include keyboard transmitting (KBD CTRL) to the Part as a whole, XA CONTROL where you can dynamically transition AWM2 Elements mid-note. You are playing back a series of looped audio recordings, by not interrupting their signal path, you can, again, stop transmitting to them as you activate a new set of looped recordings to be triggered. And the AssignKnob/Super Knob system allows you to design overlapping “fade in/fade out” type transitions (morph) as you may require. You might add Motion Sequences to the list of methods to create morphing transitions between instruments, as you can automate parameter movements in unique ways.

Hope that helps.