Scott of the Antartic
1948 technicolor movie of Captain Scott's adventure to the South Pole in 1912. As his ship leaves the dock in England, a Navy band (of course Navy) is playing a farewell tune and at the very end, last shot of the band you will see a brass colored euphonium, upright bell. Small bore tuba just earlier in the film. Euphonium sighting is about 28 minutes into the film.