-the number of beams that indicates the length of the sub-group. Note
-that @code{baseMoment} defaults to one over the denominator of the
+the number of beams that indicates the metric value of the subdivision.
+If the group following the division is shorter than the current metric
+value (usually because the beam is incomplete) the number of beams
+reflects the longest possible subdivision group. However, if there is
+only one note left after the division this restriction isn't applied.
+Note that @code{baseMoment} defaults to one over the denominator of the