Definitions can be saved as "modernGregorian.ily" in order to be used as \include "modernGregorian.ily"
Syntax is:
\include "modernGregorian.ily"
...
\cadenzaOn
\omit Stem
'note'...
\melisma { \lst 'note' \mli 'note' \sli 'note' \tli 'note' }
where:
\lst goes for long stem
\mli goes for medium ligature
\sli goes for short ligature
\tli goes for teeny ligature
It also includes a simple ornament: 'note' -\tweak extra-offset #'(X . Y) \orn
Known issues:
"modernGregorian.ily" does not support midi output.
\melisma does not follow key signatures.