Music hall developed as a form of popular entertainment in Britain in the 19th century. It's a mixture of songs, comedy, speciality acts such as conjuring, and other variety entertainment. Initially, performances took place inside public houses where the patrons were busy drinking and smoking, but before long landlords realised the benefits of creating larger spaces specifically designed for entertainment - and these became known as music halls.
By the 1850s, music hall entertainment was becoming so popular that public houses all over Britain were demolished and replaced by purpose-built theatres. These were designed so that audiences could still consume food and alcohol and smoke tobacco in the auditorium while the entertainment took place.