Negative keyswitch values? (eg C-1)

I’m beginning the long journey of writing out an expression map for Spitfire Audio BBCSO. Was having trouble getting keyswitches to work for a while, until I finally realized that BBCSO has many of their keyswitches set to negative values. In other words, legato is set to C-1, which is not a hyphen, it means one octave below C0. When I enter “F#-1” Dorico actually interprets that as “F#0”.

If I could get Dorico to recognize these values, it’d make things a little simpler because I could have a lot more instruments using a single expression map, rather than, say, using low note triggers for high strings and high note triggers for low strings. Having universal triggers would be simpler.

Not a huge deal, since I’m bumping up against the lack of universal standards and 3rd party software, but I still thought I’d ask.

Edit: I think I figured it out but I’ll leave this up in case it’s helpful to others. It just came down to the “middle C” issue. BBCSO and Dorico’s default are different by one octave. Mystery solved.

Dorico uses the C4 convention for middle C (as does Sibelius, Finale, MusicXML, Scientific Pitch Notation and many others). Historically though, at some point sample library and DAW producers adopted the C3 convention. Most of the sample libraries I’ve looked at use the C3 convention, except for Spitfire and VSL. So ensure that the control in the Expression Maps dialog is set to C4 and don’t worry about the negative values - C-1 is valid in the C4 convention.

It’s pretty simple to set up the BBC SO expression map once you have the C4 convention and have note velocity for shorts and CC1 dynamic for longs.