Two academics from Oxford University claim to have uncovered fairly compelling evidence that Shakespeare didn't work alone.
According to a press release on the university website, which first appeared in the Times Literary Supplement, Professor Laurie Maguire and Dr Emma Smith studied All's Well That Ends Well (1606-7), and cited evidence including vocabulary, unusual stage directions, and rhyming patterns that point to one particular co-author: contemporary playwright Thomas Middleton.
"We are not saying that Middleton and Shakespeare definitely worked together on All’s Well," said Dr Smith, "but Middleton’s involvement would certainly explain many of the comedy's stylistic, textual and narrative quirks. "
"The narrative stage directions - especially "Parolles and Lafew stay behind, commenting on this wedding" - look as though it is the point at which one author handed over to another."
Professor Maguire said: "The proportion of the play written in rhyme is much higher than usual for Jacobean Shakespeare - 19% of the lines are in rhyme, which fits Middleton’s norm of 20%."
Maguire also said that one word in particular stood out as suggesting Middleton's influence: "ruttish" (Act 4, Scene 3) - "a word whose only other occurrence as an adjective is in Middleton's The Phoenix. [The play] also sees an unusual number of Middleton’s known spelling preferences."
While Middleton has previously been named as having added scenes to versions Macbeth and Measure for Measure, this is among the most compelling evidence yet to suggest true co-authorship with Shakespeare, who is also known to have co-written "The Two Noble Kinsmen" (with John Fletcher) and, most modern editors agree, at least half of "Pericles, Prince of Tyre" early on in his career.
Dr Smith explained: "Where we know Shakespeare worked with other playwrights, it tended to be in a master-apprentice relationship - with Shakespeare as the apprentice in the early years and as the senior writer in his later years.
"But if, as we suspect, All’s Well and Timon of Athens were written in 1606-7 while Shakespeare was in the middle of his career and working with a dynamic, up-and-coming playwright like Middleton, the relationship seems not unlike an established musician working with the current "big thing" and is about more than just professional training."