Stephen Schwartz entered Bernstein’s life at a crucial moment when the composer needed assistance in writing Mass, especially with the lyrics for English ‘tropes’ that transmit much of the show’s message and political commentary. Schwartz has stated that he also helped Bernstein develop the loose plot that ties Mass together as an organic whole, an assertion that has been accepted by the Leonard Bernstein Office. Bernstein and Schwartz were very rushed and worked through the score mostly in performance order with little time for revisions. This chapter includes biographical material on Schwartz before he worked on Mass and his recollections of which lyrics he wrote for the show, his opinions on Mass and the work’s continuing popularity, his memories of working with Bernstein, how Schwartz later revised his lyrics for Mass, and how he has felt the influence of the older composer in his own Broadway works.