At its best, Bozzetto's 'Allegro non troppo' surpasses 'Fantasia'. If the whole film had been as good as its finest two or three segments it would be a masterpiece. It is somewhat marred, unfortunately, by the comedic live action segments involving the animator and orchestra/conductor, which appear between the musical sequences. They're not really bad. They just get a bit tedious.
In 'Allegro non troppo' a tryannical conductor terrorises an animator who is dragged from a jail cell (animation cel - deliberate pun, surely) and forced to 'draw' the animation sequences live as the orchestra (comprised of old ladies) plays. This isn't a bad framing device, and you can see why Bozzetto more or less had to push the thing as a comedy/parody, but the sad fact is that these segments (which get really goofy. Especially the one with the gorilla) undercut the genuine achievement of the animated sequences. Those sequences, if they don't quite equal Disney's technical standards, surpass 'Fantasia' several times in their emotional depth and poignancy.
The three best examples, probably in ascending order, are Debussy's 'Prelude to the Afternoon of a Faun', where an aging satyr attempts to seduce the forest maidens. There is a real sense of the isolation and loneliness of a single, late middle aged man in this piece, and it manages to be funny as well. Already we're way out of the sort of subject matter which Disney's charter would allow them to approach, and this gives 'Allegro' a definite leg-up.
This sequence is nothing though compared with Sibelius's 'Valse Triste' (Sad Waltz), in which a lonely cat wanders through an empty, crumbling building, experiencing flashbacks of a former life when he lived there as part of a family. We don't know why the building is abandoned - a war, perhaps? The effect is extremely poignant though, and totally clobbers anything in 'Fantasia' for emotional impact.
The real highlight though, and the piece which the film will probably always be remembered for, is Ravel's 'Bolero'. This lenghy animation tells the entire story of the evolution of life on earth, starting with a single celled organism that grows in a coke bottle tossed out of a UFO by aliens, and progressing up through dinosoaurs as they march across the planet, the whole procession watched by a disturbingly intelligent and malicious looking monkey. For my money this even beats 'Night on the Bald Mountain' for its dramatic impact and the matching of the music and animation (and I don't say that lightly, because 'Bald Mountain' is a hell of an achievement - though like most of 'Fantasia', it somehow fails to reach me at a gut level.)
'Allegro non troppo' isn't a parody of 'Fantasia', as the standard story seems to insist. With the possible exception of the Faun sequence recalling Beethoven's Pastoral Symphony in the Disney movie, there is nothing satirical here - not of Disney, anyway. But had Bozzetto gone and made such a film without acknowledging that some American animator called 'Pisney' or 'Grisney' had done something like it first, I suppose it would have been shot down as an imitation. That isn't to say that Bozzetto's love of comedy wouldn't have surfaced in some other way, I suppose.
'Fantasia', for all its boldness, merely opened up a new genre. What is often celebrated as unique in 'Fantasia' is little different in many respects to what film composers have always done with live action movies - which is simply to use music as an emotional adjunct to storytelling. It just happened that 'Fantasia' was animated, and that the marriage of animation and music became the sole focus of the work, rather than a supporting aspect of it. To think that nobody else should ever attempt a work in this genre again seems completely ridiculous, but in the nearly 50 years since 'Fantasia', this concept seemed to have become popularly considered Disney's property.
Bozzetto's best pieces match and probably surpass Fantasia's. It's a shame that he felt it nescessary to have quite so much hamming around between segments, or to be so self-conscious about someone having ventured into the same territory before, though I guess it does give the film a pleasingly whacky, subverisive edge.
I'd say this film has at least three classic sequences, whereas 'Fantasia' has only one or possibly two. It could easily have been a four star film, and even so, it's a must-see for the several standalone sequences which really work. The animation isn't in Disney's league, but the imagination, storytelling, and general artistry in other respects is more than a match.