The OLD stable version of LilyPond is designated 1.8
You can download an old stable port
skeleton for lilypond-1.8 here. (md5)
Simply untar in /usr/ports/print/.
fetch http://foo42.de/distfiles/ports-print-lilypond-1.8.2.tar.gz tar -xvz -C /usr/ports/print -f ports-print-lilypond-1.8.2.tar.gz (cd /usr/ports/print/lilypond-1.8 && make all install clean)
Note: for lilypond-1.8 mftrace is optional, but required per default. If you prefer not to build PFA type 1 fonts, set WITHOUT_PFA_FONTS=yes for building and installing in your make environment.
Not available, you may use the current stable Lilypond-2.0.3, it provides many new and good features.
pkg_add http://foo42.de/distfiles/packages-4.8/lilypond-1.8.2_1.tgz