Operas and musicals are similar in many ways but they are also quite different. Nevertheless, many people are not quite sure how they differ. One obvious difference is that operas are usually considerably older but this is not the only one.
Operas such as "Don Giovanni" and "Fidelio" are classics of Wolfgang Amadeus Mozart and Ludwig van Beethoven. They are from a time period which predates musicals. However, operas such as Giacomo Puccini's "Turandot" are considerably more recent. Along with Giacomo Puccini, Giuseppe Verdi is one of the most famous composers of opera. Without doubt, "La Traviata" and "Aida" are two of Giuseppe Verdi's most popular operas. "La Boheme" and "Madame Butterfly" are among Giacomo Puccini's most popular.
Operas are almost always completely sung. In essence, operas are long songs which tell a story. However, this is not the case with musicals. They are better known for their stories and acting. Thus musicals can be characterized as stories which have songs. In an opera, the music is foremost but in a musical the story takes precedence.
The music of operas and musicals is also different. Operas often have very elaborate orchestras with a wide range of instruments. This is not always so with musicals. The music of operas can be classified as classical music. In the case of musicals, the music is usually much more contemporary.
The training necessary to sing opera is usually far more rigorous than that required for singing a musical. As a result, many opera singers also perform in musicals. Musical performers, however, often dance and act very well. They do not focus on singing as much as those who perform opera.
Operas and music share a number of similarities. The two tell a story through music. However, operas predate musicals. Operas use music to tell a story and musicals tell a story with music. In addition, the two use different musical styles. The style of opera is classical and that of musicals is contemporary.