Changing staff size for certain instruments

Regardless of the general choice of 16pt or 20pt staff sizes, it is now possible to assign certain instruments – not sperate staffs belonging to a same instrument – to have narrower staff size. This is done by giving a special definition of normalshapemediumseriesnormalshapemediumseries\staffspacingr where r is the roman numeral of the instrument considered. For example, if the second instrument (starting from the system bottom) is required to have 25% narrower staffs, one only hase to declare:


normalshapemediumseries\defnormalshapemediumseries\staffspacingii{ 0.75}


before the starting command normalshapemediumseries\debutmorceau.

Not only does this statement change the vertical spacing between staff lines, but is also changes the size of the key, accidental and note symbols to fit the modified staff line spacing. However, the existence of discrete font scales for music symbol typing results in some reasonable restrictions of the values of normalshapemediumseriesnormalshapemediumseries\staffspacingr : recommended values are approximately 1, 0.8 and 0.64; if different values are chosen, then the symbol size is taken smaller than the line spacing, which may lead to readable but rather ugly typesetting.

As an example, we give two bars of the Ave Maria by Charles GOUNOD using the first prelude of Johann-Sebastian Bach's Well Tempered Clavier (transcription for organ, violin and voice, thanks to Markus VEITTES):


\begin{music} \computewidths \sepbarrules \generalmeter{\meterC}\relax ... ...tes\vert\ibbu2i0\qh2k\qh2f\qh2h\tqh2k&\qp&&\qp\enotes \finextrait \end{music}

This example was coded as: 

\def\nbinstruments{4}
\sepbarrules
\generalmeter{\meterC}\relax
\def\oct{\advance\transpose by 7\relax}
\def\staffspacingii{0.64}
\def\staffspacingiv{0.64}
\cleftoksi{{6}{0}{0}{0}}
\cleftoksii{{0}{0}{0}{0}}
\cleftoksiv{{0}{0}{0}{0}}
\nbporteesi=2\relax
\nbporteesiii=0\relax
%
\debutextrait
\normal\elemskip=0.02\hsize
%Takt 9
\Notes\zhl c\raise27pt\qs\qupp e|\ds&\oct
  \itenu5h\hl h&gra---&\itenl4h\hu h\enotes
\Notes|\ibbl0j3\qb0h\tqb0l\enotes
\Notes|\ibbl1k0\qb1o\qb1h\qb1l\tqb1o\enotes
\temps\Notes\zhl c\raise27pt\qs\qupp e|\ds&\oct
  \tten5\ibl4c0\qb4h&&\tten4\ibu5g{-3}\qh5h\enotes
\Notes|\ibbl0j3\qb0h\tqb0l&\oct\qb4a&---&\tqh5a\enotes
\Notes|\ibbl1k0\qb1o\qb1h&\oct\qb4b&ti-&\cu b\enotes
\Notes|\qb1l\tqb1o&\oct\tqb4c&a&\cu c\enotes
\barre
%Takt 10
\Notes\zhl c\raise27pt\qs\qupp d|\ds&\oct
  \qlp d&ple---&\Ilegu4k\pt d\qu d\enotes
\Notes|\ibbu1g3\bigaccid\qh1{^f}\tqh1h\enotes
\Notes|\ibbu2i0\qh2k\qh2f\enotes
\Notes|\qh2h\tqh2k&\oct \cl e&&\tleg4\cu e\enotes
\temps\Notes\zhl c\raise27pt\qs\qupp d|\ds&\oct
  \ql d&na,&\qu d\enotes
\Notes|\ibbu1g3\qh1f\tqh1h\enotes
\Notes|\ibbu2i0\qh2k\qh2f\qh2h\tqh2k&\qp&&\qp\enotes