I have a situation where I have a synthesizer player playing two different sounds at once. I would expect to have the right hand on one sound (synth lead) and the other on the left hand (synth brass). Proofreading gives me a warning that there isn’t time to change instruments but Engrave mode shows both staffs, so it seems okay. But…
I would like to know if anyone has advice on notating synthesizer players in Dorico with multiple patches on one synth or possibly two synths with more than one patch each. I am working with an orchestration for a full orchestra for a musical that has one synthesizer player but need to reduce the full orchestration to only four or five musicians for a workshop/production and am thinking that having three of those musicians playing synthesizers might come closest to representing the sound of the full orchestration.
I have separate instruments for each patch and then just have them all in one player. Instrument changes are handled automatically. If I ever needed two of the same patch in different players (which has never happened) then I would need duplicate instruments.
But… I’ve never had to have two different sounds at once in each hand.
Check out AudioModeling’s new PolySWAM (now finishing its beta). It will play multiple instruments, assigning a different one to each pitch. Supports “breakouts” where you can hold a chord (ensemble) and have one of the instruments “solo”! Pretty slick, but it loses a little functionality on a monosynth (like an EWI) — still it does play multiple voices even on that! 
— Jim
@Gregg_Butterfield, are you using multiple patches on a “split” keyboard? (I’ve not tried to send MIDI or playback info like this.) Have you done this kind of thing with a DAW?
— Jim
I think I found the answer. I had forgotten that I had asked a similar question some time ago. The two staffs in a grand staff can be set to different endpoints. In Dorico help just do a search on “Enabling independent voice playback.”
In Edit Instrments, I just set up the Synth Lead instrument to have a grand staff then enabled independent voice playback in Play mode, routed the endpoints of the two staffs as appropriate, deleted the music from the Synth Brass instrument and copied it into the bass cleff staff of the Synth Lead Grand staff. Then I changed the instrument clef on the second staff to Treble Clef 8 Below to get the notes down into the staff. I might want to play with the clef later but the music plays correctly. So now I’ve got a different patch on each hand.
Hi @Gregg_Butterfield, just to add that if you need to record live MIDI in a situation when you have a grand staff with Independent Voice Playback (one patch for the upper staff and one patch for the lower staff for example), you need to activate the caret for the staff that you want to record before clicking Record: doing so you will hear the right patch and Dorico will “print” the recording on the correct staff.
(Here a very simple example of the setup which uses only factory sounds, just in case):
two patches on grand staff IVP.dorico (1.5 MB)
I am looking to do something similar to reducing a full orchestral arrangement to a piano part, only, in my case, reducing to several synth parts with two (or more) patches loaded on the synth for any given song. So, this post was asking about how to notate it in Dorico and to get it to play back like the synthesizer players would during a performance.
And I think I have figured it out. It looks like an instrument can have multiple staffs associated with it (not just one or two). This is done by going to setup mode, clicking on the “…” to the right of the instrument name, then clicking Edit Instrument Definition. Then in Playback mode you have to enable independent voice playback. Then you can route each staff/voice to a different endpoint (equivalent to a different patch). I haven’t tested above two staffs (grand staff) yet though.