I think the experimentiation in the '90s mostly revolved around technology. CAPs (or whatever it's called), the ballroom in B&tB, the stampede in TLK, the crowds in Hunchback, the jungle in Tarzan, and the warriors in Mulan all come to mind. Of course, there were also the darker stories and unconventional (for Disney) endings in Pocahontas, Hunchback, and Tarzan; and some newly complex characters, like Frollo and the Beast; stronger and/or more-developed women characters in Ariel, Belle, Pocahontas, Mulan, Megara, etc. I would even say the depiction of male characters excelled, since male characters Walt-era are mostly uninteresting barring a few exceptions. Aladdin's and Hercules's approaches to comedy were also fairly different to most Disney comedies before them. And, of course, the design of the films were put on huge display. While a large number of Walt-era films rely exclusively on the comfortable, round, fairly realistic designs, most of the '90s created a distinct look for each film (Hunchback, Pocahontas, Mulan, Hercules) which extended even to their protagonists.
Overall, I do think the Walt-era does show more experimentation, considering it was when the medium was new and unexplored. But I don't think the Renaissance was missing its own unique aspects. Yes, the Broadway formula is a bit overplayed and there were some repetitive story choices (which isn't a flaw that's entirely absent from the Walt-era films, btw), but I don't think it makes the period any less innovative.
Just wanted to say, YES! I SO agree with everything you wrote. I hate when people paint the Renaissance films all with the same brush because they use a similar structure and a few basic, older than time story points.
Let's look at each film individually:
The Little Mermaid - a mostly under-water feature that harkened back to some of the animation techniques the studio hadn't used since, arguably, Sleeping Beauty. The effects work here is especially noteworthy and the early-use of CGI wasn't JUST limited to those ugly stairs. If you notice, the opening scene of the film uses a CG ship, the wedding barge at the end is also CG, if I recall. There are also numerous instances of CG fish (the fish that swim by the palace before the scene where Triton discovers 'Ariel is in love.' The fish that swirl around Ariel during Under the Sea, etc.) The Black Cauldron was the first film to use CG (the smoke from the cauldron itself, I believe?), the Great Mouse Detective was the first that really gave CG a run for its money (the clock-tower gears during the climax), but the Little Mermaid's use of CG could and should be called revolutionary for its time. Impressive? No. But revolutionary? I'd have to say yes. The artistic style of the film isn't really note-worthy. Unlike the later films, there isn't really a consistent theme or style to the production design.
The Rescuers Down Under of course is historical. First CAPS film, yadda yadda.
Beauty and the Beast - The film's artistic style is based more on European story books, a la Snow White and Pinocchio. (Though not at that level of artistry.) The romance is also pretty revelatory. We hadn't seen a straight-up romance this developed and believable or integral to the film ever before in an animated film. (And don't give me that Lady and the Tramp crap!)
Also pretty revolutionary: the Ballroom sequence, which needs no explanation, and the songs. I honestly think the songs need to be considered revolutionary. Mermaid started the trend, yes, but the songs in that film, with the exception of Poor, Unfortunate Souls, don't really carry the weight of the story as much as the songs here do. With the exception of Be Our Guest and Gaston, if you removed the songs, the film would be incomprehensible. In Mermaid, you could, in theory, get rid of Fathoms Below, Under the Sea, Kiss the Girl, Les Poissons and still have a film that made sense. (Not that you'd WANT to, of course.) That's a majority of that film's numbers. BatB was more revolutionary in the way it integrated its musical numbers into the heart of the story. You NEED 'Belle,' or you don't have any context of Belle's life in the village and how Gaston and the villagers contrast with her. You need her Reprise to understand how she feels. Be Our Guests, while an AMAZING song, is just Belle being fed dinner. Gaston, while a favorite, is just the town singing about how awesome he is. Its Reprise, however, IS integral. Without it, we don't get Gaston's scheme to lock up Maurice or any insight into how he operates as a person. Something There and Beauty and the Beast bring focus to Belle and the Beasts' relationship and make the love story more believable and provide the audience an emotional center. The Mob Song is basically our climax.
Aladdin - an adaptation of 1001 Nights, a folk tale. The artistic style is based on Al Hirschfeld and the distinctive curly line-work found in Arab calligraphy. Our color palette is based around contrasting hot and cool colors to symbolize good, evil and neutrality.
The Lion King is designed to resemble traditional African art. It is revolutionary in that it is the first feature film in the Disney canon to not be a direct adaptation of a previously existing work. Also: the wildebeest stampede.
Pocahontas is revolutionary in that it the first Disney film to be based on Historical events. The film's design work is inspired by a mix between the English painting style of the period and native american folk art. The angular designs for the humans was also revolutionary. The so called 'Disney style' isn't really seen in the humans here, with their almond eyes and distinctly unrounded faces. The animals, however...
The Hunchback of Notre Dame - the first Disney animation to be based on ADULT literature. I won't go into the story, songs or strong character writing and will just focus on technical details: this film rivals some of the early Walt classics when it comes to the ambition of the camera work. The multi-plane pan through the streets of Paris in the opening scene, the last shot of Out There which starts from the moment Quasi hops onto the rail to belt out the last few notes and continues to pull back as the birds swoop in front of the camera, CONTINUES, unbroken as it pulls further and further back, CONTINUES to pan down into the streets and DOESN'T CUT until Phoebus has full walked up. That shot is INSANE for animation! And the CG background characters in the Topsy Turvy sequence were damn revolutionary at that time. I believe until Treasure Planet's crescent moon sequence, Topsy Tuvry held some sort of record for the most characters in a shot. The film's artistic style is based on medieval art.
Hercules with its design work by Gerald Scarfe was the first feature Disney film to be based entirely around mythology (though Fantasia's Pastoral Sequence also incorporated Greek myth into its story, it was only ONE segment of that film.) The film's artistic style is reminiscent of paintings on Grecian urns.
Mulan, designed to reflect Chinese painting, calligraphy and water color.
Tarzan is pretty unoriginal in its design, pretty much recycling the idea of African art and jungle art seen in both The Lion King and The Jungle Book. However, the use of deep canvas, allowing the camera to move FREELY around the 2D characters WAS revolutionary.
To dismiss these films with, "oh, they're all so formulaic" is a gross oversimplification and belittles their individual achievements. Yes, in some cases, they are just as impressive as several of the Walt films. Add in nostalgia and its easy to see why this period is so beloved by fans.
I PREFER the Renaissance, having grown up with them. But when you stack these 10 films (I'm counting Rescuers Down Under) against the 19 films made under Walt, of course anybody would say that those original 19 are most historically important. There is nobody who would contest that. I like the Renaissance more. I watch them more often. But I can appreciate the IMPORTANCE of the Walt films more while still preferring the Renaissance overall. And that doesn't make me a plebeian.
But you cannot argue they weren't revolutionary. I'm sorry. You just can't. And when you look at all these films' styles, there are few repeats. They mostly all LOOK different and even SOUND different. The musical styles in each film ARE NOT the same and I HATE IT when people say that just because they're all musicals, they're all the same.
Mermaid has sea-shanties, calypso, German-Expressionist, and traditional Broadway style songs. Beauty and the Beast has waltzes, Maurice Chevalier, Cole Porter, baroque AND traditional Broadway style songs. Aladdin has eastern influences, in addition to Jazz and particularly Cab Calloway style songs. The Lion King uses African tribal music, Pocahontas mixes historical sounding English and Native American style tunes. Hunchback is famous for its powerful Latin influenced score and songs. Hercules uses Gospel. Tarzan uses pop songs... All are different from one another. All are distinctive in their styles and influences. Mostly, they are pastiches of past styles blended together (especially the Ashman/Menken stuff.) Menken has a LOT of range.
Please excuse any typos, I'm a terrible proof-reader at times.
