When you go to the theatre do you expect audience to be talking; do you expect audience to tell the performers when they are not providing adaquate entertainment; do you expect the audience to attack provokative performers? John McGrath does!
The main reason is that his theatre, the popular theatre, is performed not to audiences but to people.
Away from the escapist world of proscenium-arch theatre, with its well-defined structure, traditionalism, high ticket prices and nowhere to get a decent pint is a more human side of theatre where people are actually entertained with variety. McGrath explains from top-to-bottom in this definitive guide the differences between the middle-class audiences, the working-class people and the nature (class and form) their theatre takes.
Aswell as a thorough description of the genre of popular theatre, (incidentally also of the mainstream genre), it is eye-opening for anybody who has not experienced theatre out side of a designated theatre building - more so anybody who has only experienced city playhouses and Royal Courts.
The book closes with an analysis of theatre's relationship with politics and with TV and cinema.