The union was founded on 18 February 1906, after discussions between the show business social club and charity the Grand Order of Water Rats (GOWR); the Music Hall Artists Railway Association, which negotiated concessions on rail fares for travelling performers; and the Terriers, another club for variety performers.
It launched a weekly newspaper, The Performer, and in early 1907 staged its first industrial action, which became known as the Music Hall Strike.
It agreed to arbitration, chaired by George Askwith, and this proved a success for the union, which reached national agreements on codes of conduct, contracts and dispute resolution.
It campaigned against "ex-enemy aliens" from Germany being allowed to work in British music halls after the First World War, and also had a strained relationship with the Actors' Association, the forerunner of Equity.
[1] In the 1930s, it also campaigned for its members not to broadcast on radio, on the grounds that it would "shorten the life of [the performer's] material [and] lessen the value of his act as a going concern".