The font installation in LilyPond.

Background

This is a short overview of the installation of the Feta fonts
in LilyPond. This structure is used by default from version 
1.5.37.

Let $DATADIR denote the Lilypond data installation directory, 
typically /usr/local/share/lilypond/ or /usr/share/lilypond/.
A non-default path can be specified using 'configure --prefix'
or 'configure --datadir'.

The trick used is to let $DATADIR be the root of an additional
texmf tree, where the TeX tools can search just as it searches
the default texmf tree of the teTeX distribution. We follow
the official TeX Directory Structure (see `texdoc tds`). 

The main advantage of putting the font files in a teTeX
system tree is that generated font files (such as .*pk files)
will automatically be stored in "the right place", i.e. you
should never end up in your current working directory - something
that was a common problem in previous Lilypond installations.
What is then considered "the right place" in teTeX? If the user
has write permissions in $DATADIR (for example if the installation
is done locally in a home directory), then the generated files
will also appear in subdirectories of $DATADIR. This means that
you can keep several LilyPond versions installed in parallel
as long as $DATADIR is set separately for each version and you 
have write permissions in (at least all but one) of the installation
directories. For ordinary installations in /usr/share/ or 
/usr/local/share/, where the user does not have write permission, 
the generated font files will instead appear in the directory
specified by `kpsexpand \$VARTEXFONTS`, often /var/tmp/texfonts/
or /var/spool/texmf/ depending on your teTeX distribution.

Details

The files are installed in the following subdirectories:

$DATADIR/fonts/source/: all *.mf files
$DATADIR/fonts/afm/: all *.afm files
$DATADIR/fonts/tfm/: all *.tfm files
$DATADIR/fonts/type1/: all *.pfa and/or *.pfb files
$DATADIR/tex/: all *.tex files
$DATADIR/dvips/: the lilypond.map file

To make teTeX aware of the files, the directory is added
to the list of texmf trees by setting the single variable
$TEXMF. 

In Bourne shell/bash:
TEXMF="{$DATADIR,"`kpsexpand  \\$TEXMF`"}"
export TEXMF

In csh/tcsh:
set noglob
setenv TEXMF "{$DATADIR,"`kpsexpand  \$TEXMF`"}"
unset noglob

If $TEXMF was set previously, kpsexpand will use that value, 
otherwise it is read from texmf.cnf (`kpsewhich texmf.cnf`
tells you where to find the file). 


Creating nice-looking PDF files

If you have generated and installed the so-called Type1 versions
of the fonts, and have Ghostscript version 6.0 or later, you can
make PDF versions of your scores that look nice both on screen 
and on paper. You just have to tell dvips to use the Type1 
version of the fonts:

dvips -ulilypond.map -Ppdf myscore.dvi
ps2pdf myscore.ps

If you want top quality printouts, it is recommended to stick
to the bitmap fonts, i.e. to call dvips directly without
any extra flags. The resulting PDF files will then unfortunately
look fuzzy on screen.

This will work well with ly2dvi output, however if you 
use lilypond-book or write a LaTeX wrapper file yourself,
do NOT include the line \usepackage[T1]{fontenc} since
the Type1 text fonts included in the free TeX distributions
only include TC encoded fonts, not T1 encoded. However,
add \usepackage[latin1]{inputenc} if you use any non-
anglosaxian characters.