+@aitem{cluster}
+
+A @emph{cluster} is a range of simultaneously sounding pitches that
+may change over time. The set of available pitches to apply usually
+depends on the acoustic source. Thus, in piano music, a cluster
+typically consists of a continuous range of the semitones as provided
+by the piano's fixed set of a chromatic scale. In choral music, each
+singer of the choir typically may sing an arbitrary pitch within the
+cluster's range that is not bound to any diatonic, chromatic or other
+scale. In electronic music, a cluster (theoretically) may even cover
+a continuous range of pitches, thus resulting in colored noise, such
+as pink noise.
+
+Clusters can be denoted in the context of ordinary staff notation by
+engraving simple geometrical shapes that replace ordinary notation of
+notes. Ordinary notes as musical events specify starting time and
+duration of pitches; however, the duration of a note is expressed by
+the shape of the note head rather than by the horizontal graphical
+extent of the note symbol. In contrast, the shape of a cluster
+geometrically describes the development of a range of pitches
+(vertical extent) over time (horizontal extent). Still, the
+geometrical shape of a cluster covers the area in which any single
+pitch contained in the cluster would be notated as an ordinary note.
+
+@lilypond[fragment,relative=2,verbatim]
+ \apply #notes-to-clusters { <c e > <b f'> <b g'> <c g> <f e> }
+@end lilypond
+
+
projects / lilypond.git / blobdiff