Final answer:
A musical is a show with a narrative arc and popular songs, exemplified by classics like Guys and Dolls and West Side Story. Originating from a blend of vaudeville, melodrama, and other forms of entertainment, musical theatre is a uniquely American genre that experienced significant growth post-World War II.
Step-by-step explanation:
A musical is a show that has a story—which traces the fortunes of the main characters through a series of adventures with a beginning, middle, and end—and features more popular songs. The genre of musical theatre saw a golden age post-World War II, with popular titles such as Guys and Dolls, My Fair Lady, West Side Story, and The Music Man. These musicals blended powerful storytelling with popular songs leading to an increase in musical theatre audiences, partly due to the greater accessibility provided by television at the time.
Guys and Dolls is considered one of the most perfect musicals, featuring memorable songs such as "Sit Down You're Rocking the Boat" and "Bushel and a Peck". Its plot, revolving around the pursuit of marriage, resonated with the contemporary audiences of the 1950s. West Side Story, a musical tragedy, was noteworthy for shifting the musical theatre scene with its groundbreaking themes.
Musical theatre is important because it is a combination of the three performing arts: dance, music, and theatre. It has been suggested that musical theatre is a uniquely American contribution to the arts, with a history rooted in the vibrate traditions of vaudeville, melodramas, and variety shows that captivated audiences with diverse and elaborate performances.