Opened at the Shubert Theatre on May 3, 1956. Closed December 14, 1957 after 676 performances — 19 months. The Most Happy Fella is a 1956 musical with a book, music, and lyrics by Frank Loesser. The story, about a romance between an older man and younger woman, is based on the 1924 play They Knew What They Wanted by Sidney Howard. The show is described by some theatre historians and critics as operatic. The original Broadway production ran for 14 months and it has enjoyed several revivals, including one staged by the New York City Opera. Wiki link