Broadway musicals put much of the greatness into the 20th century's Great American Songbook. Brilliant composers such as Leonard Bernstein, Richard Rodgers and Oscar Hammerstein wrote songs that singers like Zero Mostel, Julie Andrews and Carol Channing subsequently immortalised. With roots in both European drama and all-American vaudeville, musicals have demonstrated a remarkable knack for humanising the ineffable and elevating the everyday. In 1927, for instance, Show Boat blended music and song to depict a diverse community of workers and performers. Some of Broadway's more luminous productions, including The Sound of Music and Cabaret, depicted wartime travesties with grace and grit. And where Guys and Dolls and West Side Story reflect urban street life through the tuneful magic of American vernacular music, The Music Man and Oklahoma!— whose character-elaborating integration of music, song, and dance make it musical theatre's most influential work to date—found inspiration in places where the corn grows as high as an elephant's eye.