§ =214.= The strophe in ancient poetry, and the stanza in mediaeval and modern analogues and derivatives of that poetic form, are combinations of single lines into a unity of which the lines are the parts. The word _strophe_[180] in its literal sense means a turning, and originally denoted the return of the song to the melody with which it began. The melody, which is a series of musical sounds arranged in accordance with the laws of rhythm and modulation, has in poetry its counterpart in a parallel series of significant sounds or words arranged according to the laws of rhythm; and the melodic termination of the musical series has its analogue in the logical completion of the thought. But within the stanza itself again there are well-marked resting places, divisions closely connected with the periods or sentences of which the stanza is made up. The periods are built up of rhythmical sequences which are combinations of single feet, dominated by a rhythmical main accent. In shorter lines the end of the rhythmical sequence as a rule coincides with the end of the verse; but if the line is of some length it generally contains two or even more rhythmical sequences.[181] The essential constituents of the stanza are the lines; and the structure of the stanzas connected together to make up a poem is in classical as well as in mediaeval and modern poetry subject to the rule that the lines of each stanza of the poem must resemble those of the other stanzas in number, length (i.e. the number of feet or measures), rhythmical structure, and arrangement. (This rule, however, is not without exceptions in modern poetry.) In the versification of the ancients it was sufficient for the construction of a strophic poem that its verses should be combined in a certain number of groups which resembled each other in these respects. In modern poetry, also, such an arrangement of the verses may be sufficient for the construction of stanzas; but this is only exceptionally the case, and, as a rule, only in imitation of the classic metrical forms (cf. §§ 212-13). The stanza, as it is found in the mediaeval and modern poetry of the nations of western Europe, exhibits an additional structural element of the greatest importance, viz. the connexion of the single lines of the stanza by end-rhyme; and with regard to this a rule analogous to the previously mentioned law regarding the equality in number and nature of verses forming a stanza holds good, viz. that the arrangement of the rhymes which link the verses together to form stanzas, must be the same in all the stanzas of a poem.