Thanks everyone for you comments :)
For a while I've been going through a 'dry' time for original music ideas, so
have started to play with MIDI files to keep my hand in so-to-speak.
@ Fons I didn't know the story in the opera and you're right it was the
'Apocalypse' that I had in mind.
@ Jeanny The score shows multiple clarinets, so that's what I (effectively) went
with.
Incidentally, the reason I had two copies of Synth Strings is that the
descending glissando sections consist of dozens of overlapping notes. Yoshimi
can have up to 60 sounding notes per part and this was being exceeded, so the
answer was to alternately run two identical instruments.
--
Will J Godfrey