Radio Reunited, when the BBC's radio networks come together for a global simulcast, is happening at 5.33pm on 14 November.
Find out about the BBC Radio at 90 anniversary.
Simon Mayo's listeners and their radios mark the BBC's 90th birthday.
A collection of short programmes
celebrating memorable moments from 90 years of BBC radio including Vera Lynn, George Orwell, the Beatles and John Peel.