A small tool to automatically add trilli.
Assumes: font User1 = MusikDingsxxx
Once again, the trillo can be interpreted differently depending on the period, the composer etc. but I think this is a good starting point.
Of course, you can always do it by hand or use a hidden layedered staff, if you prefer...
Warning: exceeding 15 consecutive grace notes makes odd effects. NWC oddity.
As usual, Rick got a workaround, but it's not so easy to automate.
Update:
Corrected the default stem orientation
Corrected the case of rest chord when the rest is not visible
Added parameter "n" or "-" to avoid adding grace notes to actually execute the trill
Version 2.00: Deeply reworked and extended
The most notable extension is for trills of arbitrary length, thanks to a trick suggested long ago by Rick-the-wizard.
A known problem is that, in long trills, if you have notes (a chord) other than the one trilling then those notes are visible but don't play.