Look up John Ball and you'll see the note. Sydney Carter's publisher is one of very few to ask that material to which they hold copyright be removed from the DT. The song is not a detailed history of the Peasant's Revolt that you seem to be requesting. And I don't remember a Jack Straw being involved in the Revolt - you may have been thinking of John Ball. The jingle of the time was "When Adam delved and Eva span, who was then the gentleman"