 The original libretto was by Lillian Hellman (qv). For the 1974  revival, a new script was written by Hugh Wheeler (qv), and it is  this script that has been used ever since. Although most of the  lyrics by Richard Wilbur (qv) the principal lyricist remained, as  well those of the other writers, director Harold Prince (qv) had  Stephen Sondheim rewrite lyrics for one song and add new lyrics  for several others that were never used in the original 1956  production of the show.