The four-note motif was also broadcast as a morale-boosting signal over Allied radio during World War 2 (even though its composer would effectively have been an 'enemy'). On what was it played in this context?

The opening movement of Beethoven's Symphony No. 5 has to be one of the most enduring 'ear-worms' of all time. It is known all over the world and regularly appears in culture including pop music, film and television.