Extravaganza

An extravaganza can refer to a range of things, e.g. an elaborate party, a festival or an artistic fantasy.

In theatrical terms the reference could be to a literary or musical work marked by extreme freedom of style and structure and usually by elements of burlesque or parody, or an elaborate theatrical production, such as a large circus or some musicals.

By analogy, it was popular in the 19th century as a term to describe travestiy or burlesque versions of classic theatrical works as well - probably with reference to the fantastical, "over the top", style often employed in such works.

See also Travesty or Burlesque