problem with tablature mode and 7-string guitar

[Stef Epardaud]

Hello,

This is my first message on this list, but i've searched the archives
for stringsTuning and the search returned only patches.
I am completely new to lilypond and i'm very confused by the syntax,
although i'm sure it can do everything (almost) i want it to.

My problem is simple: i have a 7-string guitar, so i want to see a
7-string tablature, and after much tweaking, i almost got it to work
with:

\include "a4-init.ly"
\include "italiano.ly"


part = \notes {

 \time 7/4
  si,,-1 mi,-2 la,-3 re-4 sol-5 si-6 mi'-7

}

\score {
 \context StaffGroup <
  \context Staff <
     % Hide fingering number
     \property Staff.Fingering \override #'transparent = ##t

   \part
   >
  \context TabStaff <
    \property Staff.Stem \override #'direction = #1

  \part
   >
 >
 \paper {
  \translator { 
    \TabStaffContext
    \name TabStaff
     stringTunings = #'(-25 -20 -15 -10 -5 -1 4 9)
     StaffSymbol \override #'line-count  = #8
     StaffSymbol \override #'staff-space = #1.5
  }
 }
}

i had to put 8 strings and invent the last one because if i put:

     stringTunings = #'(-25 -20 -15 -10 -5 -1 4)
     StaffSymbol \override #'line-count  = #7

then the fret numers in the tablature are all written one line too high,
and that makes the last string written above the tablature altogether,
while the first string is never reachable.

making it 8 strings allows me to print and then "erase" the lowest line
to get back to 7 strings and have all fret numbers on the line.

surely there must be a way to get the fret numbers on the tablature
line, but i fail to understand how, could you help me please ?

another question is regarding tremolo variations on the guitar, is there
any support for this:

       +2
       _ 
      / ~~
-_ -2/
  \ /
   V

i'm not sure how it's called, but it's a way of describing how and when
to pull or push the tremolo bar and by how many tones, it's widely used
in electric guitar tablatures.

thanx very much for any help.
i am finally able to give my bassist readable tablatures, thus avoiding
the eternal complains about unreadability :)
-- 
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