Wow, that's seriously weird... my old coffee maker used to beep in weird patterns, but never full-on classical music. Maybe there's a hidden speaker or something from the factory? I'd check for any buttons you might have pressed by accident. Or it's just finally achieved consciousness, which, you know, good for it I guess...
Hold on, it just started playing a whole symphony out of nowhere? That's not just a beep, that's a full concert from a tiny metal box! Where would it even hide a speaker big enough for Beethoven, in the crumb tray? My brain can't handle the idea of my breakfast fighting back with classical music. Honestly if my appliances rebel, I'd expect angry static, not something that fancy.