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Musical patterns that recur in approximate, rather thanidentical, form within a composition (or body of musical work)are considered to be of considerable importance in musicanalysis. Here we consider the ``evolutionary chain problem'':this is the problem of computing a chain of all ``motif''recurrences, each of which is a transformation of (``similar''to) the original motif, but each of which is progressivelyfurther from the original. Here we consider several variants ofthe evolutionary chain problem and we present efficientalgorithms for solving them.