Oh it most undoubtedly was written with the idea that they're playing something along the lines of our own world's classical music. There's, well, a whole lot of things that make zero sense referred to as they are without the context and origins from our own history behind them. Some much more glaring than this, you've got a couple mentions of 'gunboat diplomacy' floating around for instance, in a world that lacks firearms.
Most people will honestly not even question this instance, and Wolf proposed an acceptable hand wave here with it just being old empire music, so as much as the worldbuilding critiqueslave in me wants to grumble a bit, I'd say it's not that big of an issue.