-Note that the second voice differs from the first one only by the
-additional keywords @code{\startCluster} and @code{\stopCluster} and the
-fact that notes, accidentals, etc. are hidden. A future version of
-lilypond may automatically hide notes, accidentals, etc. within the
-scope of clusters.
-
-Also note that a music expression like @code{< @{ g8 e8 @} a4 >} is
-illegal; in such a case, you can instead use the expression @code{< g8
-a8 > < e8 a8 >}.
-
-By default, cluster engraver is in the voice context. This allows
-putting ordinary notes and clusters together in the same staff, even
-simultaneously. However, in such a case no attempt is made to
-automatically avoid collisions between ordinary notes and clusters.
-
-The geometrical shape can be further controlled with grob properties
-@code{padding} and @code{shape}. @code{padding} adds to the vertical
-extent of the shape (top and bottom) and is expressed in units of
-staffspace. Since the pitch range of a single pitch is infinitely
-small, if padding is set to @code{0.0}, this possibly results in an
-invisible shape, if you,for example, say @code{ \startCluster c d e
-\endCluster}. The default value for @code{padding} therefore is
-@code{0.25}, such that a single pitch roughly shows the same height as a
-note head. Property @code{shape} controls how the overall shape of the
-cluster is constructed from the set of notes. Currently supported
-values are @code{leftsided-stairs}, @code{rightsided-stairs},
-@code{centered-stairs}, and @code{ramp}.