Iambic pentameter was used in Macbeth because the people of the Renaissance were infatuated with the Greeks (Neoclassical). The term originally applied to the quantitative meter of Classical Greek poetry, in which an iamb consisted of a short syllable followed by a long syllable.

Shakespeare was merely a product of his time - writing what the people wanted. I’m sure that if he wrote during a different era in history, his style would have reflected the pop culture.

The blank verse was used so liberally because he used rhyme as stage direction. Remember that the stages at his time often did not include sets, props, or even costumes most of the time (only the very wealthy could afford them). Notice that he rhymes at the end of scenes - this would alert the audience that the scene was ending - when everyone left (exeunt is Latin for “they all leave”) the stage and the last line was a rhymed couplet. When the stage was sometimes emptied during scenes, he would not have a rhymed couplet.

The rhyme plus the empty stage alerted people that scene was ending and that they should listen to the first line of he next player to understand the setting or description of the new scene.

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