'The Rock' was an essential step in T.In it he taught himself how to write choral lines in greek fashion and in the style of the english morality plays'Everyman'.A request for a pageant play to raise funds for church building started Eliot off on his quest for a modern poetic drama.The effectiveness of 'the Rock'choruses ensured that the device would become an important feature of 'Murder in the Cathedral',although in the later the effects were more varied and dramatic.
The Canterbury Festival had begun in 1928 with John Masefield's 'The Coming of Christ'.Canterbury was not only the arch-diocese of the country ;it was the most ancient Christian shrine in the land ,santified by the 'hooly blisful man whose cult was the reason for Chaucer's Canterbury Piligrim's journey.When George Bell, Bishop of Chicester, invited Eliot to write for the 1953 Canterbury Festival the poet still chose the martyr for his subject despite a 1932-3 production of Tennyson's play.
The conditions were congenial to Eliot.He had a Christian subject and a Christian audience to be gathered at one of Europe's most famous Christian shrines.He had a director withwhom he could work, and he had the chance to further the cause of poetic drama.The topic martyrdom attracted Eliot ,as did the nature of the events and its significance for a modern audience. That significance was brought out through the choruses, and the emotional structure of the play is based on them rather than on Thomas's exercise in self-analysis.For that was the point of the Festival;the ordinary human response to the exceptional events, the martyrdom which repeats and reminds us of Christ''s own sacrifice. Ritually the play comments a fresh on an act whose meaning may have been lost in the familiarity of the outward story.
The play had the advantage of referring to a well-known, highly dramatic story of a confrontation between two powerful personalities, both historically and spiritually significant.