My unsolicited advise to those who intend to watch this movie is to watch extra the documentary about the real Polka King, Jan Lewandoski, as then there's a valid conparison to the real persona vs. Jack Black's portrayal as Jan Lewan ( americanized version of his name). Black's portrayal is funny and genuine. The suspicious mother in law is a superb character who adds spice to the Jan Lewan saga , in those days Jan might have pioneered the pyramiding scam not by evil intentions but perhaps out of wanting to satisfy every one else. There is a confrontation scène near the end between the mother in law and some alleged victims which rings true - one gets scammed because one is too greedy thus deserves it. Pay no attention to the humpahpah music but focus on the motivation of real people and what it results to, this is what this film is about.