What's a patent theater?

Frank Crummell: The patent theatres were the theatres that were licensed to perform "spoken drama" after the English Restoration of Charles II in 1660. Other theatres were prohibited from performing such "serious" drama, but were permitted to show comedy, pantomime or melodrama. Drama was also interspersed with singing or dancing, to prevent the whole being too serious or dramatic.http://en.wikipedia.org/wiki/Patent_theatre