Style, in music where pitch alone is serialised, stems from decisions about repetition. The set can be used in such a way that, even if restatements of one particular form are frequent, a different register, rhythm and timbral distribution will make it difficult to hear the restatement as repetition, at least before close analysis. Serial composers who retain the essentially traditional, pre-serial method of melodic or motivic identity are perhaps more likely to use repetitions which possess a clear similarity of shape as well as an explicit element of variation. Such a method can ensure the audibility of the evolving structure of a serial work, and also enable a composer to use designs involving tonal emphases without recourse to triadic formulae.