One of the earliest animation-set-to-classical-music cartoons(pre-Fantasia) and also to me one of the finest. One where the animation, music and mood of the cartoon is so brilliantly done that one can ignore the lack of plot and originality(both of which The Blue Danube was never about in the first place).
What immediately stuck out as particularly great with The Blue Danube is the animation, The Blue Danube has to be one of the most beautiful-looking 30s(and perhaps even ever) non-Disney cartoons, and some of in the second half of the cartoon shows some good visual imagination. Particularly striking about the animation is the most exquisite use of colour I've ever seen in a cartoon and the effortlessly graceful movements on the Fairy, the rotoscoped design blending with the traditionally drawn backgrounds without jarring a jot. The colourful and meticulously drawn background art cannot be overlooked either.
Also outstanding is the music. The music, which for the entirety of the cartoon is the On the Beautiful Blue Danube waltz by Johann Strauss II(aka. The Waltz King), is one of those cases where one runs out of superlatives describing how good it is. It is a wonderful piece of music, one of the composer's most famous works for good reason, and has been used to iconic effect before in animation(i.e. A Corny Concerto) and in films(i.e. 2001: A Space Odyssey), it is also used brilliantly here and merges with the visuals without fault.
The animation and music are what make The Blue Danube, but the cartoon's sense of mood and the feeling one gets out of it are wonderfully done too. As said before, one shouldn't expect much from the story structurally, structurally the cartoon is pretty thin(one of those cases here though where that is not a bad thing) and not much new. That's completely forgivable though because the cartoon is never dull, it has a very natural flow and there is a real sense of harmony throughout.
The Blue Danube is also very high in charm and imagination(loved the idea of how the Danube turned blue, imaginative and didn't dissolve into silliness), the characters are among early animation's most adorable(without being too cutesy or sickly sweet), there's some cool imaginative animation with the dam and one's left grinning from ear to ear and in a good mood throughout the whole seven minutes(that's how happy The Blue Danube makes you feel during and after watching). There's no dialogue, meaning that the animation and music have more room to shine, and shine they certainly do.
In conclusion, one of the most beautiful cartoons ever made. 10/10 Bethany Cox