Here's how you'd specify a weird looking beam that instead of being
horizontal, falls two staff spaces:
+
+[FIXME]
+
+
@lilypond[fragment,relative,verbatim]
\property Voice.Beam \set #'staff-position = #4
\property Voice.Beam \set #'height = #-4
[c8 c]
@end lilypond
+[TODO: doc autokneeing ? ]
+
@c TODO -> why this ref? Document?
@cindex @code{neutral-direction}