Definition:
A story-based stage production in which the characters sing their dialogue. Typically, the music of an opera is "classical."
What makes an opera different from a musical? In most operas, the focus is on the singing -- rather than on a combination of song and dance. Also, most opera performers sing in a classically trained vocal range, strikingly different than most musical theater performers.
Examples:
Don Giovanni by Wolfgang Amadeus Mozart.
