The point is that these ornaments should go next to the notes to which they refer, and not necessarily above or below the staff. This little example of a few bars indicate some of the difficulties, taken from the 4th book of "Pièces de Violes" by Marin Marais, published in Paris in 1717:
You'll see various bowing marks (actually there's only one used here: "e", which stands for the French "enfler": "swelling"; that is, a bow-stroke without the customary "attack"), x's and commas for ornaments, numbers with dots indicating fingers and which string, and next to the double-stopped d and f-sharp in the third and final bars what looks like a broken cross; this is a "barre", indicating a single finger laid over two or more strings at once.
What I'm trying to do is to retain as much as possible of this notation in Lilypond. I could probably bodge up quite a lot of this if there was some way of placing expressions next to the notes themselves - but I can't find out how to do that.
Any advice would be gratefully received!
Thank you very much,
Alasdair