\mudelafile{stem-tremolo.ly}
+Abbreviation beams (official naming?) are a kind of repeat symbol.
+To avoid confusion, abbreviation beams do not touch the stems, but
+leave a gap. Abbreviation beams on half notes are not ambiguous,
+and should touch the stems.
+
+\mudelafile{abbreviation-beam.sly}
+
Beams, stems and noteheads often have communication troubles, since
the two systems for y dimensions (1 unit = staffspace, 1 unit = 1
point) are mixed.
\mudelafile{stem-direction.sly}
+Similarly, if \verb+stem_default_neutral_direction+ is set to \verb+-1+.
+
+\mudelafile{stem-direction-down.ly}
+
\section{Grace notes}
Grace notes are typeset as an encapsulated piece of music. You can
\section{Lyrics}
Lyrics can be set to a melody automatically. Excess lyrics will be
-dumped. Lyrics will not be set over rests. You can have melismata by
-setting a property melismaBusy. If you want a different order than
-first Music, then Lyrics, you must precook a chord of staffs/lyrics
-and label those. Of course \verb+\rhythm+ ignores any other rhythms
-in the piece. Hyphens and extenders do not assume anything about
-lyric lengths, so they continue to work.
+dumped. Lyrics will not be set over rests. You can have melismata
+either by setting a property melismaBusy, or by setting
+automaticMelismas (which will set melismas during slurs). If you want a
+different order than first Music, then Lyrics, you must precook a
+chord of staffs/lyrics and label those. Of course \verb+\rhythm+
+ignores any other rhythms in the piece. Hyphens and extenders do not
+assume anything about lyric lengths, so they continue to work.
\mudelafile{lyric-combine.ly}