Cinema organs

In the days of silent movies, mood accompaniment to the film was provided by a pianist who skillfully adjusted the music to the scene on the film; I am not old enough to have seen any of these. Maybe because of the piano, some larger cinemas introduced a cinema organ. The one that I remember well was at the Davis theatre in Croydon and, in the interval (there used to be two films, an A and a B feature) whilst ice creams were sold in the aisles, a very large electric organ used to slowly rise from the centre of the stage with an organist playing away as it rose.  I have a vague recollection of there being a radio programme called (someone) at the cinema organ.