I'm currently using ABC notation for all of the score examples on my website and converting it to notation using abcm2ps. I have run into a limitation with it and need something more flexible. However I still wish to use a textual notation and do not want to hand edit images as this would make things much harder to change in the future.
In order for lillypond to be a viable option I need some custom symbols, the most critical being the Irish roll symbol, which is an arch, like a fermata without the dot. I've seen that lillypond can use snippets of postscript, however I do not want to learn postscript just to get this finished. Is it possible to define these externally, such as an svg file, and include them?
I am discussing the different ways of notating the finger articulations used in Irish and other trad music so cannot substitute the symbol. Note that an Irish roll and a turn are not the same. It would be useful to define a number of other symbols, including the ones used in Grey Larson's whistle notation.