Adding the Schleifer to the ornaments list
I could find various threads asking for a solution regarding this ornament on the various Lilypond forums, but none of the workarounds proposed until now seem to fit.
Here are two exemples of how it appears in the music:
As you can see, the ornament is attached to the note at its right, but starts on another note's height. There should be the possibility to chose the note's height on which it has to begin, adding lines outside the staff if needed (see 1st example). And, of course, it would not collide with the bar line on the left (which is the problem I get trying to use it in a markup context). The workarounds proposed until now seem to always use the schleifer in the middle of a bar, so with at least a note preceding the schleifer in the bar, and rely on that note, or on an invisible note to set the height of the base of the schleifer. In the examples you can find attached, the schleifer appears in the beginning of the bar, so I can't use those techniques.
Thank you !
Best wishes, Francesco Intrieri.