In The Words and Music of Paul McCartney: The Solo Years, Vincent Benitez writes: "The Broadcast is the most experimental track in Wings' entire output." David Bowie was reportedly so impressed by the track, which appears on the 1979 album Back to the Egg, that he thought it should be released as the first single. Technically, the track isn't a song at all, but a spoken word piece heard over a fragment of melody--and the words aren't spoken by Paul McCartney or anybody else in the band.
The track was recorded at Lympne Castle in Kent, England, which dates from the 12th century. The castle was owned by a gentleman named Harold Margary and his wife Deirdre. Benitez quotes Wings guitarist Laurence Juber:
It's a bit hazy but the guy that owns the castle where we were recording, both he and his wife had these very plummy kind of voices
. . . . I think it was like, "Oh, wouldn't it be fun to have them read some classic English literature material and use the orchestral background to be just this kind of weird interlude." And they were game for it.
McCartney selected books at random from the castle library and recorded the Margarys reading selections. Harold Margary read from The Sport of Kings by Ian Hay and The Little Man by John Galsworthy, which is what you hear on the final track. Deirdre Margary read lyrics from a song called "The Poodle and the Pug," from a 1946 light opera called Big Ben. "Her reading didn't make the final version," reports Ian Peel in The Unknown Paul McCartney, "but a few lines ('...with tufts of hair stuck here and there which one would like to tug...') were spliced into Reception," another track on the album.
The Words and Music of Paul McCartney: The Solo Years (Kindle Edition)
The Little Man (Kindle Edition)