What is an oratorio and what different between it opera?

An oratorio is a musical composition for an orchestra and choir, usually based on a religious theme, and typically performed in a church or concert hall. It is similar to an opera in that it has a dramatic structure and includes soloists, but it differs from an opera in that it is typically not staged, and the plot is usually more focused on spiritual themes than on human relationships.

Here are some of the key differences between oratorios and operas:

- Subject matter :Oratorios typically have religious themes, while operas can have a wide variety of subjects, including historical, mythological, and everyday life.

- Musical structure :Oratorios typically have a more complex musical structure than operas, with more use of counterpoint and fugue.

- Staging :Oratorios are not typically staged, while operas are.

- Audience :Oratorios are typically performed in churches or concert halls, while operas are performed in opera houses.

Some famous oratorios include:

- Handel's "Messiah"

- Bach's "St. John Passion"

- Mendelssohn's "Elijah"

Some famous operas include:

- Mozart's "The Marriage of Figaro"

- Verdi's "La traviata"

- Puccini's "Tosca"