Well interestingly, Hemato plays a Flamenco guitar, and hired a Mariachi at her girlfriend's funeral. The culture of the first half of the story is more like Latin America ( but in this case French-America ) during this timeline. In the second half, it would make more sense for the made character to play a syntheized Shamisen guitar.
There is an odd language fusion between 2045-2085 that makes the lyrics sound somewhat distinct even within the same 6-6-5-6-6 syllabic rhythm:
Francaise dekimasu ka, ou parlez-vour Nihongo?
So it's a distinct language in some ways from Parisienne French. I could however see the music being imported into Parisienne night clubs however.
That's kind of what happened with Andalusia and Southern Spain.
I still need to think about what the lyrical structure of Modern Hafestra is going to be like though. It's completely phonetically unrelated to French in many ways.