There's actually a large variety of possible changes in your snippet. I
assume you're not proposing all those alternatives? If not, could you
state which is the preferred solution, and not include the others? That
would make it simpler to implement.
There is actually not so much variety. There is one alternative. I
omitted the \italic, because right now it is italic by default.
But my suggestion for the text is:
\markup \bold \italic \concat {
\bold "8" \fontsize #-2 \translate-scaled #'(0 . 0.85) "va"
}
and similar for 15ma and 22ma and
\markup \bold \italic \concat {
"8" \fontsize #-2 "vb"
}
and similar for 15mb and 22mb.
And for the lines, like Gould says: top aligned for alta and bottom
aligned for bassa.
Is it clearer now?
Joram