Trying to get my head around a situation when a VST provides a different instrument for what is actually just a different playing technique. For instance, the VSL Special Edition decides to have a completely different instrument for a trumpet playing mute instead of adding the articulation to the instrument. Bad programming if you ask me but what’s the easiest way to get around this in Dorico? Obviously you can’t add a different instrument to a player as it’s the same instrument. You could pretend that Trumpet 2 for instance always plays mute. But that’s hardly elegant or realistic. There’s probably a clever way which I just can’t think of. Sibelius more or less sorted it out through its (otherwise often frustrating) sound ID system.
If you are using Vienna Instruments (Pro) you can switch between matrices just as easily as you can switch articulations within a single matrix.
In other words, you can put the muted instrument in one matrix and the normal instrument in another and switch between them using key switches e.g.
That means you just precede the regular key switch for muted with the key switch for the correct matrix.
For this to work you still have to use combined techniques in the Dorico expression map, Natural + mute, Accent + mute etc.etc.
of course – I simply need to move the mute matrix (or individual patches) into the main instrument so then I won’t need the mute instrument at all, and then the rest follows in the Expression map… Thanks for switching on my brain 
Aside from VI (Pro), Dorico playing techniques can change the MIDI channel number, either by a relative increment or to an fixed channel number.
So you can set up the VSTs in Play mode so different instruments match up with your playing technique definitions, and then save this as a custom playback template.
The problem with using Midi Channels is that the dynamic level isn’t inherited between the channels, resulting in volume jumps. (This was mentioned in another thread some time ago, and I’m personally hopeful that this will be fixed relatively soon.)
Initially the above didn’t work until I realised that you can only paste in VI Pro and I’d accidentally loaded an old preset with standard VI slots. But now it’s doing what I originally planned. And the MIDI channel idea could also come in useful if indeed I needed to keep a separate instrument – had completely forgotten about this possibility.
Huh, that might explain some things for me. I’ve just been automating and griping at the sample library. Well, they probably deserved it anyway…
To get the same thing with the VSL Synchron library, you are recommended not to mixed patches from different instruments because of the different timbral impulses and indeed, you can hear a difference in the sound if you do this. So the channel change seems best here and it’s worked fine for me. Perhaps my test project is not demanding enough to be affected by the volume jumps but if fratveno would be good enough to give a specific example of what can go wrong, then I’ll try it out.
Don’t forget that in Dorico you can have different voices on the same staff with different midi channels. This is an incredible function. If your Muted Trumpet is on a different midi channel, simple put those notes into a new voice (upstem voice 2 for example) and assign that voice to your muted trumpet midi channel in PLAY mode by toggling the All Voices switch on the channel. The Expression Map can then stay the same for unmuted and muted notes probably. You can indicate ‘mute’ in the score for your muted notes, but if you use a Playing Technique for this direction, then I would suppress playback on it because you don’t really want it to do anything…Alternatively, use system text or similar.
indeed – I’m aware of this useful feature though thus far I have a separate clef so haven’t tried it. A single Expression Map can easily accommodate both mute and non-mute in the Synchron or VI Pro variants. In the former, you just need to set a relative channel of 0 for the main instrument in the default (ord or nat patch) and 1 for the mute articulations, thus making it flexible if you change the orchestral setup.