Is there a way to separate a single midi track with multiple program changes so that each program change (and notes) are put on their own midi track?

I'm sure this question is clear to you, but it does not come across clearly to me. You can certainly place MIDI data on separate Tracks - each track can transmit on a separate MIDI channel. Program Changes, like MIDI note-ons and controller messages fall under the category of MIDI messages called CHANNEL MESSAGES. So for example, a Track in Cubase AI set to transmit OUT on MIDI channel 1 can contain the Program Change, Control Change, and Note-on messages for all receiving devices set to receive channel 1. That is always going to be true.

Is there a way to filter out notes for a single program change where a midi track contains multiple changes?

? I do not understand this question, please rephrase.

I want to assign a midi channel to the program changes on my MX.
ie: a bit like midi dissolve but for program changes.

Program Change messages are already CHANNEL MESSAGES - you do not have to do anything to assign them but put them on a MIDI Channel addressing the MX PART you want to control.

One thing that you should know: Separate MIDI TRACKS are only necessary because it make it easier to view them. All MIDI CHANNEL MESSAGES like Note-ons, Controllers and even Program Changes messages include the MIDI channel. So only one MIDI track is really ever necessary. You DISSOLVE PARTS simply to make it easier to group all messages for a particular channel together.

A Note-on message for triggering middle "C" at a velocity of 100, on MIDI Channel 1, for example, would be represented by the following coded message: 90 3C 64
A Note-on message for triggering middle "C" at a velocity of 100, on MIDI Channel 2, would be represented by the following coded message: 91 3C 64

These two messages could be on the same track when the MIDI OUT Channel is set to "ANY" - they would not interfere with each other. Or they could be DISSOLVED (by Channel) to separate tracks... where each Track was assigned to a separate MIDI channel number.

"90" translated as "nine-zero" represents a NOTE-ON (9) on MIDI channel 1 (0)
"3C" translates as Note 60 which is Middle C on a Yamaha
"64" translates to the Velocity value of 100

"91" translates to NOTE-ON (9) on MIDI channel 2 (1)
"3C" is Note 60 (again middle C
"64" is Velocity of 100

A MIDI Track in Cubase that is set to MIDI Channel = ANY means that the messages will be read as written. So all 16 MIDI Channels can, indeed, exist on a single MIDI Track - IF that MIDI Track has its Channel set to "ANY"

If a Cubase MIDI Track's MIDI OUT is set to MIDI Channel = 1 then all messages on that Track will be RE-CHANNELIZED to Channel 1.

Now that all said, when you create a PROGRAM CHANGE message, it will include the MIDI Channel. If you place it on a separate Track and set that Track's MIDI OUT to a specific MIDI Channel then the Program Change message will be re-channelized to the Channel you select for the entire TRACK.

There are 128 Program Changes in MIDI. As you may realize your MX has far more sounds than 128... this is where BANK SELECT messages come into play. The sounds in the MX are spread out over several BANKS - each BANK has a coded message that precedes the Program Change.

Bank Select 63, 0 Program Change 1 would recall the "Concert Grand" Piano
Bank Select 63, 1 Program Change 1 would recall the Organ sound "Roundabout"
Bank Select 63, 2 Program Change 1 would recall the Guitar sound "2 Coil Harm"

What is it you want to do ... you can, of course, place Program Change messages in your Track to change the sound that is playing on that track. It takes about 100-200ms to change sounds. And while this is much quicker than a human being can switch instruments, you must respect that in music 100-200ms is a significant amount of time. While a tenth or twentieth of second is faster than you can do most things, in music at a tempo of 120 beats per minute, one second is two beats. The snare drum playing the back beat (2 and 4) -the strikes are exactly 1 second apart. So a Program Change is not immediate. But if you have 100-200ms of silence on a track you can switch instruments without it being heard.

Lets say I have one midi track using midi channel 1.
On this track there are 3 program changes and notes as you said above.
All I want to do is move each program change to its own midi track so that all piano notes appear on one track, organ sounds on another and guitar sounds on the third.
Therefore I have 3 midi tracks instead of one, then I should be able to assign voice changes to each midi track and remove the program change from automation.

I can do this manually, but I wanted to know if there was a quicker way?

Thanks for the useful information as always.

Cheers.

I can do this manually

Good, because I believe that's how you must do it. Use the Scissor tool to make a Cut at the appropriate points; then simply drag the data to a new track also assigned to Channel 1.

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