Thanks, it works great !
I personnally prefer the minus sign which is a little shorter.
However, i had to write this complicated markup to obtain a correct "7
/ b5" for semi-diminished chords (instead of the dashed circle).
<c ees ges bes>- \markup { "-" \super {7/ \hspace #0.2 \teeny
{\raise #0.3 \flat} 5} } % C dashed circle -> C-7/5b
It seems that the \flat inside the \super does not behave like the
rest of the text, and is bigger and to low than the usual superscript
text, but I could not figure why, reading the Overview of Markup
commands. Has anyone a clue ?
(http://lilypond.org/doc/v2.8/Documentation/user/lilypond/Overview-of-text-markup-commands.html#Overview-of-text-markup-commands
<http://lilypond.org/doc/v2.8/Documentation/user/lilypond/Overview-of-text-markup-commands.html#Overview-of-text-markup-commands>).