What is the author's style in J. B. by Archibald MacLeish?

J. B. is written entirely in verse, which was a common form for English drama in earlier centuries (many of Shakespeare's play, for example, are written in iambic pentameter verse) but extremely rare in the 1950s. When the play did well on Broadway, critics marveled that a play in verse could find an audience. J. B. is written in unrhymed four-stress lines without strict meter.