I can't check it out directly right now to see if I get the same here, but you might find this helpful if you want to examine, tweak, add to, or even create brand new soundworld expression maps.
http://www.sibelius.com/download/sse/main.htmlPersonally I've found that it seems to work well out of the box, but I never noticed that the soundworld tables in Sibelius may have ignored some of the available instruments.
Do the ones that show up work properly? Generally they are triggered by things you enter as text, or by symbols or other markings you put on the score. You can 'edit' what markings do in the Playback Dictionary, which can send MIDI events directly, or defer behavior to the soundworld.xml expression map table.
You can also select patches in ARIA manually, and drop key switches (or other MIDI events) directly onto the score as text. Check the MIDI section of your Sibelius manual for more info...
They can be entered in the form: ~Nnote,velocity for
NoteOn, and ~Onote,velocity for NoteOff. (You must insert a NoteOff message, or your note
will sound forever!).
As an example you could enter as text in the score:
~N27,64 ~O27,64
The tilde tells Cubase to hide this text from printing. This would send a quick quick key-switch for MIDI note 27 (A0) without printing it.
For things you use frequently you can also make your own text based switches in the play-back 'Dictionary'.