Ballet
Part of speech: noun
Definition: A classical form of dance. A theatrical presentation of such dancing, usually with music, sometimes in the form of a story.
Opera
Part of speech: noun
Definition: A theatrical work combining drama, music, song and sometimes dance.The score for such a work.A building designed for the performance of such works; an opera house.A company dedicated to performing such works.
Example sentence: One of the most wonderful memories in my life was when I sang at the Opera House in Sydney. I will never forget that. It is one of the most beautiful Houses I have ever sung in my life.