Towards A Checklist For Troubleshooting Virtual Instrument Playback Problems

Recently while working on Dorico elements for a customized playback of virtual instruments (in my case, VSL Synchron), elements such as with Playing Techniques, Playback Techniques, Expression Maps, and Endpoints, I thought it might help me to compile some sort of checklist. This I could refer to as I tried to determine the cause(s) of any problems I encountered.

I thought I’d share what I’ve come up with so far in hopes that:

a. any errors, omissions, or misunderstandings on my part might be corrected by your comments in this thread.

b. the result might be helpful to any others like me who sometimes cannot figure out the precise cause of a breakdown in the many-faceted process of going from notation to customized VI playback.

(Note, I will not include matters having to do with basic audio or MIDI connections.)

The checklist so far is divided into broad categories as follows:
Expression Map
End Point
Play Track PT Lane popup

I have abbreviated Playing Technique as “PT” and Playback Playing Technique as "PBT.



  1. In Setup mode, is the instrument is assigned to Player
  2. In Play mode, is the VST instrument in the VST Instruments Rack
  3. In Play mode, is the track assigned to the correct VST Instrument
  4. If using VE Pro, is the Track routed to the correct MIDI port and channel
  5. In the VST player, verify everything needed is present, enabled and working
  6. If using VE Pro, are the instance and channel enabled

Techniques (PT and PBT)

  1. In the Write mode PT panel, is the intended PT listed and defined
  2. In Write mode, is the PT added appropriately to the notation
  3. In the Play mode PBT editor, is the intended PBT listed and defined
    (I always define PBTs as Attribute, this checklist assumes the same)
  4. In the Write mode PT editor, is the PT associated with the proper PBT

Expression Map

  1. In the Play window for Ex Maps, is the needed Ex Map listed
  2. In the Ex Map entry, is the entry assigned to the correct PBT,
    whether single or combination
  3. In the Ex Map entry, are the mapping assignments correct,
    (KS’s, CC’s, etc.)

End Point

  1. In the Play mode End Point panel, is the instrument properly listed
    with correct MIDI port and channel
  2. Is the instrument assigned to the correct Ex Map

Play Track PT Lane popup

  1. This is a Dorico feedback opportunity to check what’s actuallly happening,
    which may vary from what you want to happen
  2. (I still have some questions as to the exact meaning of some elements below,
    and welcome any clarification or instruction)
  3. Base switch, active Ex Map entry Base Switch, first shows entry label, then assigned PBT’s
  4. Internal effects, limited to “hard-coded” PT like legato, marcato, etc ?
  5. Active techniques, appear to be PBTs not PTs
  6. Expression map, active map from End Point
  7. Channel, from Play Track
  8. VST connection, from End Point

There remain two, more vague troubleshooting categories that I have not yet included because, though I know they exist, I don’t sufficiently understand the possibilities or the solutions.

I believe that despite correct setup for various entries, there might be conflicts that prevent the expected execution. For example, ExMap entries that refer to the same PBT. Or duplicate PTs or PBTs. There may be others I am unaware of. The solution here is clear, eliminate the duplication, but how, beyond and endless trial and error, does one know what conflicts are behind an unexpected problem?

Note Timing
On the forum I have on occasion read references to this problem, where the timing of a note relative to a PT/PBT might prevent it’s execution, resulting in the auto-assignment of Natural. I am not sure I am describing this correctly.

These last two categories are murky to me, so I could really use some instruction from users or staff to flesh them out.

I do not know, there may be other categories to include in this checklist. Any help or instruction is appreciated. I hope it helps not just me but anyone else in my situation. Maybe I’m just a lugnut and it’s clear to everyone else!

I will respond as best I can.

1 Like