5.4.8 Rotating objects  Both layout objects and elements of
markup text can be rotated by any angle about any point, but the
method of doing so differs.  Rotating layout objects  All layout
objects which support the grob-interface can be rotated by
setting their rotation property. This takes a list of three
items: the angle of rotation counter-clockwise, and the x and y
coordinates of the point relative to the object’s reference
point about which the rotation is to be performed. The angle of
rotation is specified in degrees and the coordinates in staff-
spaces.  The angle of rotation and the coordinates of the
rotation point must be determined by trial and error.  There are
only a few situations where the rotation of layout objects is
useful; the following example shows one situation where they may
be:  g4\< e' d' f\! \override Hairpin.rotation = #'(20 -1 0)
g,,4\< e' d' f\!  [image of music]  Rotating markup  All markup
text can be rotated to lie at any angle by prefixing it with the
\rotate command. The comm