Among all modes of literary expression, drama was the most popular, most lucrative, and most influential of the era. S. T. Coleridge, Joanna Baillie, Lord Byron, Mary Mitford were among the poets whose plays were successfully performed, and Coleridge joined Charles Lamb and William Hazlitt as critics of the drama. To shield church and state, censorship was exercised under the Licensing Act (1737). This Act granted to the licensed Theatres Royal the exclusive right to perform traditional comedy and tragedy. Originally directed to perform only musical entertainment and pantomime, the unlicensed theatres gradually introduced more spoken dialogue and relied on melodrama to attract audiences.