In pictures: Broadcasting House at 75

Val Gielgud - brother of actor John - was one of the most senior members of staff when Broadcasting House opened.

He spent 20 years overseeing drama at the BBC, working on radio productions for most of the 1930s before moving to television.

During that decade, radio actors were paid more than their TV counterparts.

This reflected the size of the listening audience, compared to the fledgling visual service.