Structure, Metrical Requirement, Repetitive Requirement, Rhyme
Accentual-syllabic with uniform line lengths except for the
shorter refrain: (Ba)baB bab abaB where B is the first word or phrase from the first line and rhymes with the last word of the second
Algernon Charles Swinburne
R/R: (Ba)baB bab abaB
B = Refrain that is first part of first line and rhymes with the b lines.