Puccini's opera 'Tosca'. 'Tosca' an opera in three acts by Giacomo Puccini premiered in Rome on January 14, 1900. Tosca is a prima Donna in love with the painter Cavaradossi, and desired by Baron...
Impossible to answer as it is totally subjective and covers all types of operas - but it is usually accepted that the most popular operas are Carmen and La boheme.
There are thousands of operas on hundreds of topics: this is like asking "what is a movie about." Popular themes are love, death, betrayal, war, and magic.
It's like a play, but the story is sung instead of simply spoken. As in a play, the characters act and there is staging. Some operas have spoken dialogue between songs; in others, everything is sung....