Soon after the Cinematograph Act came into force in 1909, small orchestras became more common in London cinemas than the lone pianist that some previous histories have identified.
Rather than responding moment-to-moment to the images on screen in the manner that an improvising pianist might (or well might not), these orchestras played through a number of well-regarded musical pieces in their entirety, which might or might not have had a direct correspondence to some aspect of the film or its theme.
Despite exhortations in the trade press for such a correspondence between music and film, this does not seem to have happened in practice regularly until at least the mid-1910s.
This according to “The art of not playing to pictures in British cinemas, 1906–1914” by Jon Burrows, an essay included in The sounds of the silents in Britain (Oxford and New York: Oxford University Press, pp. 111–125).
Below, we invite you to experiment with random film accompaniment using your own record collection.