I brought a piece over from Finale, for Bayan (Accordion, essentially) and Orchestra. The orchestra parts were voiced just fine (flute sounds like flute, clarinet sounds .....). However, the Bayan didn't sound that well. I tried to edit the instrument sound, The closest sounds I found were various organ sounds, or melodica. The melodica sounds (probably) the closest, but has a very limited range. What does Sibelius have against accordions? Am I missing something?
Idea No. 926