MacNeice's work for the BBC initially involved writing and producing radio programmes intended to build support for the US, and later Russia – cultural programmes emphasising links between the countries rather than outright propaganda. A critical work on W. B. Yeats (on which he had been working since the poet's death in 1939) was published early in 1941, as were "Plant and Phantom" and "Poems 1925–1940" (an American anthology). At the end of the year, MacNeice started a relationship with Hedli Anderson and they were married in July 1942, three months after the death of his father. Brigid Corinna MacNeice (known by her second name like her parents, or as "Bimba") was born a year later. By the end of the war MacNeice had written well over sixty scripts for the BBC and a further collection of poems, "Springboard". The radio play "Christopher Columbus", produced in 1942 and later published as a book, featured music by William Walton, conducted by Adrian Boult, and starred Laurence Olivier. 1943's "He Had a Date" (loosely based on the life and death of MacNeice's friend Graham Shepard but also semi-autobiographical) was also published, as was "The Dark Tower" (1946, again with music by Britten). Dylan Thomas acted in some of MacNeice's plays during this period, and the two poets, both heavy drinkers, also became social companions.