And it's only two because nobody ever bothered with rock'n roll.
Rules and Regulations for Public Dance Halls ("no beating of drum to produce jazz effect") and also, Nazi hatred for jazz (I think this one is my favorite: "so-called jazz compositions may contain at most 10% syncopation; the remainder must consist of a natural legato movement devoid of the hysterical rhythmic reverses characteristic of the barbarian races and conductive to dark instincts alien to the German people (so-called riffs)"...)
"An idealist is one who, on noticing that a rose smells better than a cabbage, concludes that it will also make better soup." - H.L. Mencken