Background: Rodgers and Hammerstein refers to composer Richard Rodgers (1902-1979) and lyricist-dramatist Oscar Hammerstein II (1895-1960), who together were an influential, innovative and successful American musical theatre writing team. They created a string of popular Broadway musicals in the 1940s and 1950s, initiating what is considered the "golden age" of musical theatre. Five of their Broadway shows, Oklahoma!, Carousel, South Pacific, The King and I and The Sound of Music, were outstanding successes, as was the television broadcast of Cinderella (1957). Of the other four that the team produced on Broadway during their lifetimes, Flower Drum Song was well-received, and none was an outright flop.
Context: Rodgers and Hammerstein re-worked the musical theatre genre. Early 20th-century musicals, except for the Princess Theatre musicals and a few important examples like Hammerstein and Jerome Kern's Show Boat, were usually whimsical or farcical, and typically built around a star. Because the efforts of Rodgers and Hammerstein were so successful, many musicals that followed contained thought-provoking plots with mature themes, and in which all the aspects of the play, dance, song, and drama, were combined in an integrated whole. Stephen Sondheim has cited Rodgers and Hammerstein as having had a crucial influence on his work.  Rodgers and Hammerstein also use the technique of what some call the "formula musical". While some hail this approach, others criticize it for its predictability. The term "formula musical" may refer to a musical with a predictable plot, but it also refers to the casting requirements of Rodgers & Hammerstein characters. Typically, any musical from this team will have the casting of a strong baritone lead, a dainty and light soprano lead, a supporting lead tenor, and a supporting alto lead. Although there are exceptions to this generalization, it simplifies the audition process, and gives audiences an idea of what to expect vocally from a Rodgers and Hammerstein musical. However, this formula had been used in Viennese operetta, such as The Merry Widow.  William A. Everett and Paul R. Laird wrote that Oklahoma!, "like Show Boat, became a milestone, so that later historians writing about important moments in twentieth-century theatre would begin to identify eras according to their relationship to Oklahoma!" In The Complete Book of Light Opera, Mark Lubbock adds, "After Oklahoma!, Rodgers and Hammerstein were the most important contributors to the musical-play form - with such masterworks as Carousel, The King and I and South Pacific. The examples they set in creating vital plays, often rich with social thought, provided the necessary encouragement for other gifted writers to create musical plays of their own."  In 1950, the team of Rodgers and Hammerstein received The Hundred Year Association of New York's Gold Medal Award "in recognition of outstanding contributions to the City of New York." They were also honored in 1999 with a United States Postal Service stamp commemorating their partnership. The Richard Rodgers Theatre in New York City is named after Rodgers. Forbes named Rodgers and Hammerstein second on its list of top-earning dead celebrities in 2009 at $235 million. In 2010, the original film arrangements of the team's music were restored and performed at the Proms concerts in London's Royal Albert Hall by the John Wilson Orchestra.
Question: What other techniques did they introduce?. Whats the answer?
Rodgers and Hammerstein also use the technique of what some call the "formula musical".