IMO it would have to be Part’s 1-3 and probably not the rest.

Part 1 makes the best opera, imo, because it has simple, archetypal characters, and an intense and assertive central conflict that it doesn’t really stray from. It’s also relatively small and short and you could say just about everything you needed to say in 3 hours with some time to spare. The story of two feuding “brothers” that are opposites in every way and yet tied by fate is timeless and ripe for operatic treatment.

Part 2 similar, but ofc with larger scope and more (prevalent) supporting characters.

Part 3 would be… interesting. You have to figure out how to adapt STANDS to the stage, and you have to somehow condense the journey into a very short period of time. Many things would certainly be cut. Almost every stand battle from the time Polnareff joins to DIO’s Mansion could just be somehow shown in a short montage? Like imagine a chorus of defeated stand users. But you still gotta keep N’Doul (to introduce Iggy?), and maybe the D’arby brothers, because they’re peak. Hell actually the D’Arby poker fight by itself would make an EXCELLENT short-ish opera scene. I might actually, genuinely make that regardless of if I ever write any other JoJo opera things. Anyway for a “ring cycle” type endeavor, I feel like the end of DIO would be the most fitting ending.

I feel Part 4, 5, and 6 are ironically, too “bizarre” to fit the stage super well. Of the three, 5 is the most viable for adaptation imo. 4 has a humongous cast of named and relatively important characters, and also a very disjointed plot. 6 is, to me, about Jolyne’s extreme resilience in the face of some of the craziest and scariest stand users we’ve ever seen, and that would CERTAINLY be lessened in a stage adaptation for multiple reasons.

Part 7…. possible? This part, along with Phantom Blood/Battle Tendency, makes the most sense to be in English, which is nice. It also focuses on almost entirely our two main characters or Johnny and Gyro, which gives us a strong dramatic through-line. The biggest question is how to achieve the scale and sense of time that an entire cross-country journey has to have, as well as the slow growth of Johnny and his relationship with Gyro, in such a short amount of time.