Early on in the US involvement in World War II some bright young radio-telegrapher noticed that the opening of the 5th (Da da da daaah) mimics the dot-dot-dot-dash in Morse code for the letter V.
The music instantly shot to the Top of the Charts for one and all because of the association with the slogan "V for Victory."
MAny a person age 65 or older - who knows nothing whatsoever about classical music will recognize Beethoven's Fifth Symphony because of the association

(A person now in 60s would have been old enough in 1941 - when war started for USA - to remember the many playings of the Fifth Symphony. I recall the Fifth played on every radio station many times on both VE Day and VJ DAy. )