Yes, Grupa MoCarta is a Polish group and I can’t understand a lick of what they’re saying, but I had a blast watching them (videos below). They’re all well educated instrumentalists who graduated from prestigious Academies of Music in Warsaw and Łódz, but they decided to play classical music in a humorous way. "What’s more, they created something like a musical cabaret, one in which the music, not the words were the source of laughter."
The power of their jokes can be characterized like this: they take a classical composition as canvas, analyze its structure and theme, and surround it with musical associations. So while listening to the final product one is constantly surprised by various musical quotations. Classically trained, they explain their intentions this way:
Enjoy!