Decasyllable
Medieval French heroic epics (the chansons de geste) were most often composed in 10 syllable verses (from which, the decasyllable was termed "heroic verse"), generally with a regular caesura after the fourth syllable.(The medieval French romance (roman) was, however, most often written in 8 syllable (or octosyllable) verse.)Paul Valéry's great poem "The Graveyard by the Sea" (Le Cimetière marin) is, however, written in decasyllables.Noting its use in the operas of Giuseppe Verdi, musicologist Philip Gossett describes the composer's request to the librettist for his opera Macbeth, Francesco Maria Piave, as follows: "I'd like to do a chorus as important as the one in Nabucco, but I wouldn't want it to have the same rhythm, and that's why I ask you for ottonari" [8 syllables; and then Gossett continues] "Va, pensiero, sull'ali dorate" from Nabucco, "O Signore del tetto natio" from I Lombardi, and "Si ridesti il Leon di Castiglia" from Ernani all employ the poetic meter of decasillabi.Chaucer[3] evolved this meter into iambs, or the alternating pattern of five stressed and unstressed syllables made famous by Shakespeare.