Tweaking a footnote

[David Sumbler]

I want to annotate a particular passage with a footnote.

So far I have managed to get what I want in the music itself with:

\override Score.FootnoteItem.annotation-line = ##f
\footnote "*" #'(0 . 3) "Theme by Louis Drouet"

This produces an asterisk over the first note of the relevant passage,
which is exactly what I want.

But there are 3 things about the footnote itself which I would like to
alter.

1) If I don't specify a mark, Lilypond puts a "1" by the grob and by the
footnote.  But if I do specify a mark, the footnote itself does not show
it, i.e. it has no asterisk (in this case) by it.  I want the footnote
to display the asterisk, otherwise it will not be clear why there is an
asterisk in the score.

2) Lilypond produces a horizontal line separating the footnote area from
the main part of the page.  I would prefer not to have this - assuming
that I can get the asterisk to be displayed next to the footnote, there
is no ambiguity about what the footnote is there for.

3) I would like this footnote centred, rather than left-aligned on the
page, but I haven't figured out how to do this.  No doubt it involves
normal markup commands, but I can't work out how to apply them in this
case.  (I have never used footnotes before.)

Thanks for any suggestions.

David