-@c has nothing to do with harps, AFAIK.
-@ignore
-Sacred Harp notation uses four shaped note heads. In the major,
-the tonic is a triangle and then proceeding up the scale you
-have circle, square, triangle, circle, square, diamond. In the
-minor, the shapes should be assigned to keep the same interval
-relationships, e.g. you assign them for the relative major. (This
-means that the scale in the minor gives the tonic a square.)
-
-@c TODO add example of \sacredHarpHeads, or a ref?
+Some possibilities:
+- glissandi
+- tremolo (for bisbigliando)
+- natural harmonics
+- directional arpeggio and non-arpeggio
+- workaroung for keeping both staves visible in an orchestral
+ score,
+http://lists.gnu.org/archive/html/lilypond-user/2007-08/msg00386.html
+and http://lsr.dsi.unimi.it/LSR/Item?u=1&id=312